everyone dies sooner or later, so, future proof
Well, as someone who has 'walked away once', it doesn't take much to realise just how immortal we all really are
That said, there is plenty of software out there that is just no longer supported at all - even though 'it could be'. Some of this is astronomy-based, and a lot of it needs obsolete operating systems to be able to run it, and even more obsolete software development packages to try and mofify it (or to even try and port it to newer environments).
Yes, our development team is very small, but the quality of the code that has resulted belies the fact that so few people are directly involved in the process. Perhaps the best that any software user can ever hope for in such circumstances is that provision may have been made for the 'PixInsight baton' to be handed on someone (or to a select few) in the event that the 'main runner' has to step away from its continued support and devleopment.
But, let's draw an analogy here - you might really, really want to buy that impressive car in the showroom. However, it is going to really stretch your budget. So, even after a really nice test-drive, and a lot of pensive pacing around the showroom, you eventually talk yourself out of the purchase because 'spare parts' or 'dealer support' might not be available in the (long-term) future. And, then you find yourself 'wondering and wishing' as you drive out of another showroom in a car that you didn't really want, and away from a salesman who was only really interested in you up until your cash was in the till (and his commission was in his bank).
Sure, you still have a new car - but you know it will always be 'second-best', and the dealer's after sales service and warranty promises are as worthless as the toilet-paper they were written on.
Perhaps the 'way forward' for PixInsight is to be like Microsoft - where you simply pay a small monthly fee until such time as you choose to stop using the software. Sure, these payments would be 'affordable' but, as the months pass, it will soon be obvious that you have payed more than the original 'one-off purchase fee'.
There are probably thousands of PixInsight users who, quite happily, can barely even remember that original one-off payment - and of that group, as I said before, many, many users who have had so much pleasure learning PI and developing their astroimages using PI, that they would pay more now.
Just remember, ownership of PixInsight is not compulsory (yet
), so make sure you have fully researched your options, and made full use of the (otherwise unrestricted) time-limited trial version before you commit.