I understand that it is a perception vs reality issue 100%.
I would be more understanding if software companies like SAI said when you purchase a software program that it will be supported for X number of years then it would stop working or no longer supported, instead of waiting for the server to die and than say we have just stopped supporting Version X.
Typically, at least from what I've seen, it's not done in terms of years, but in terms of generations of software. X, X-1 (no not the OTR show), X-2 etc.
Some, only support the current, some only 1 generation back (X-1). Some do up to 3 generations back. Depending on their release cycle, that could be a very long time or a blink of an eye (considering Adobe programs and even Corel programs seem to be on the yearly release, not long at all), relatively speaking.
But in a case like this, to not even have access to the program with no notice, in my opinion is crazy.
In my mind, it depends on how old it is in terms of generations. I'm not familiar with Flexi numbering schema, just based on speculation, I would say that it's 2 generations back. That's a grey area for sure.
They are holding the users of v10 hostage if they saved all of their designs in FS format only.
Well, all closed source proprietary programs have vendor lock in if you only save and use in their native proprietary formats. Typically why I suggest having two versions, one that is more open (or at least more widely accepted by many programs) and one that is your proprietary format.
Otherwise, you tend to have this issue no matter what.
In fact, let's say that you have some files that are ver 9 and the current version doesn't import 9 at all? No bueno for those old files, even if you are still using their software. This can actually be an issue in open source as well depending on if there were fundamental changes to a particular toolset from one generation to the next.
Where should I draw the line where I should not be upset that my program has stopped working with no notice, after 1 year, 2 years, 10 years?
Again, I do believe it's based on version generations, which I think would be better then years. The latest release cycle of my embroidery software was 5 yrs. Imagine if the EOL was based on yrs. It's quite possible that the latest version could have gone EOL before a new one was released.
What if it was your accounting program and the same thing happened?
I can't speak for everyone, but sometimes being "risk adverse" really comes into play and I always try to have as good of a backup plan that I can have. None of my admin programs are closed source, period. Some I've created some of it myself, others, I use open source (sometimes a combination of the 2). More production programs, I use a legit licensed version for as long as I can (even in VMs), but if there is ever something that prevents me from using them, I have a fall back. Not necessarily 1:1 fall back all the time, but it's something that I can still use. That's why I also try to have file formats that are as close to parity as I can get with the proprietary version, but are more widely accepted among different programs.
Again, bare in mind, I'm not saying that I like this situation at all. It's just the situation we have until something changes that forces change on how closed source software vendors do things.