We use PyCharm and love it. Could we do without it? Yes, of course. The tool makes a number of things more convenient but it isn't indispensable. That said, I'd hate to see it go.
One thing that has always bothered me about JetBrains is the "personality" of their support. It is isn't good. We haven't needed a lot of it, maybe 2 or 3 incidents since PyCharm came out (we adopted right away). Yet, there's a bothersome lag in support (I am not talking about international time zones) as well as a lack of quality. It's almost --but not quite-- condescending in feel.
I do understand there might be language and cultural differences at play here. I also have experience with German companies (not just software). Their approach to customer service can be very dry and very different from what you might experience in the US. I am guessing the Czech Republic might be similar.
I know these are generalizations that could be way off base. In the case of JetBrains, if the product was not good we would have stopped using them purely based on the substandard support.
As far as paying monthly. No. Thanks. I want my software to work and work reliably. If I chose not to upgrade for a year or two, these tools need to work. A monthly plan with 30 day call-the-mothership is a non-starter for me. I will not, ever, buy into something like that for my business. I want less overhead, not more. And I don't want a situation where if things are tight for a few months we lose half of our tools. Buying into something like that would be a really dumb decision on the part of a business owner or manager.
I look at something like MS Office. We purchased licenses back in 2007. We have not needed any of the new features. And so, our 15 or so licenses work just fine for what we need to do and we do not need to spend another dime to use the software. From a business perspective that is the right way to use tools and the right way to make purchases. You do not want to bleed money on a regular basis for software updates you don't need or updates that don't make enough of a material impact to justify their cost.
Anyhow, I hope JetBrains reconsiders. We have been looking at some of their other products but will not even consider them if they are converted to monthly subscription products. If they insist on taking this approach I suspect products like SublimeText will see a boost in adoption. Yes, not the same thing, but not the end of the world and it is a really, really good product with a very friendly license.