I bought MB in April of 2015 and I have a memory of this being a perpetual license as well. I did understand that I would not have to pay again. Having said that, I researched my old emails and found the receipt which does not include this information, but refers to the licensing terms "you accepted" on the licensing page when you purchased the license. I used the Internet archive to look for this license around that time and found it.
It does not contain the word perpetual, and I would argue that the license is not much of a license at all because it does not state what we are licensed to do, except evaluate or "use" (whatever that means exactly). It does spend almost all the text on explaining what the developer does not have to do and is not responsible for. As such, it is more of a warranty agreement and there is no mention in it of fixing problems, or providing updated functionality. Note that typical SW licenses spend a little more on the "what you are allowed to do with it", but are otherwise just as focused on promising nothing and removing liability.
Therefore it is my opinion that those of us who want or expect continued improvements have no basis (in this "license") to demand it. There is something to be said, however, for the precedent that such improvements and fixes have been provided, for free, at least since I have owned my license (April 2015). That has created an expectation. If Boris changes his mind about that, as he has, that may disappoint us, and the wisdom of that policy can be questioned, but I do not find it illegal. It is a little tacky to drop this without any lead time.
With respect to fixing bugs (which is not the same as new features), there is again no promise of that. On the other hand, when we all made a purchase we ostensibly did so based on the description of functionality of the software. To the extent that description does not match actual behavior (due to a bug), it is entirely reasonable to expect it to be fixed. After all, if it were not fixed (as a decision not to do so), it is basically false advertising.
The real problem comes over time. Since free improvements have been provided (in additional to bug fixes being incorporated) most of us now have a product that has features promised when we bought a license, as well as others we "received" since then. So valid claims w.r.t. bug fixing really only exist for the "original" features.
If one were to accept the "license" renewal, I would argue that, at that point, the "base" situation resets to whatever is advertised at that point, but arguably that is based on semantics vs intended meaning. If the fee is simple a recurring cost to keep the original license active, it would not reset things. If, on the other hand, it is a fee to "update to the latest version, along with 2 years of free updates" (essentially a discount to a new license), it would reset the situation. The language in the agreement is not clear enough, in my non-legal opinion, to make this distinction.
Overall I do not have a "legal" problem with the decision to require an additional fee every two years, provided this was clear at the time of purchase. Without that, as is the case for most of us so far, we bought a product that would only have limited life-span (2 years) unless we pay more later. Boris argues that the live-span is not limited, and technically this may be true, but practically it is not. It is like deciding to buy a car that comes for 4 years of free service and the manufacturer deciding, 2 years in, that it would only be 2 years of service and you now have to pay. Had you known that it was 2 years up front, you would have valued your initial purchase price differently and, perhaps, decided not to buy. Yes, you can continue to drive it, until there is a problem. At that point you are forced to accept the additional cost, but possibly years earlier than expected.
Overall, though, it seems extremely unwise that there is no "grand-father" provision for existing users. Of course had there been one, Boris would only start reaping the benefit of this new approach two years from now, from new purchasers and it might not fit his stated financial needs. On the other hand, the stated need arises from the increased support volume. Realistically, the need for support comes mostly from new users, or is "re-ignited" because of new features. Most existing users have their MB configured, it does what it needs to do, and they don't need support. Therefore, is the initial purchase price not enough to support these new users for 2 years?
Then there is MB PRO. I get the impression, although this may be entirely incorrect, that much of the energy is focused on this platform (between the two, not in comparison to other products). New features seem to be mostly for the PRO (and I understand that the regular version on TP-LINK HW has its limitations). I somehow doubt Boris is tracking development cost and support cost separately for both. If he were not, the statements on the cost as justification for the 2 year renewal is tenuous at best.
I get the impression that the primary target of MB was the user of the Davis line of products (it certainly seems to be the best supported). As such products are generally $700 or more, those users probably have less price sensitivity to the cost of MB. Adding in support for Ambient, Accurite etc. (the cheaper weather station platforms), may have added a solid base of additional income. Being cheaper station platforms, they probably have a wider base, but their users are likely, by and large, less sophisticated than Davis users. They probably may require some initial support, but not much after. They would be, however, quite price sensitive as even the initial cost of HW and SW exceeds or comes close to the station purchase price.
Then there is also the remainder of the product line that generates money, including licensing of the MB platform to companies such as AmbientWeather who sells the combination of license plus TP-LINK hardware under the product name "WeatherBridge". They charge $209 (May 2017), which is about double the cost of buying HW and SW license separately. I suspect that additional margin is mostly for Ambient, but who knows. Update: Ambient has confirmed to me that the licensing is with MB (and not Ambient) and thus is subject to the same introduction of recurring fees, which they believe is reasonable.
However, all that does not matter in that Boris can do what he wants, when he wants it, unless somebody is finding a legal argument to pursue (which I doubt exists) and is willing to back that up with legal action (which is no doubt cost prohibitive). Clearly, many existing users will not like this. I also have an email from the maker of at least one other weather product that MB can upload data for, stating that now that this recurring fee model has been added, he is contemplating dropping support for MB altogether. To be fair, that last opinion would likely not change, even if there was a grand-father provision. With an eye on the fact that significant further enhancements of the basic MB are unlikely (due to platform limitations), overall, my suggestion would be to remove the two year fee requirement, except perhaps for PRO users (although they paid much more, that is I suppose, mostly for hardware). Long term, that would probably be more beneficial to all, including Boris.
