I think it's also an issue of expense. If I'd bought an M-audio interface for $120, and four years later it went obsolete with no more driver support, I'd be mildly annoyed but I'd also shrug and say "well whatever, life goes on", and pony up another $120 for a product from another company. It's $120. I've spend more on a good bottle of scotch, and it didn't last half as long.
The VStudio 700, however, was a higher level product aimed at serious hobbyists and independant pros, and came with a price tag to match. It was an investment for most of us, and I think it is fair to expect that it would be treated accordingly by the manufacturer. Roland asked us to invest a fair amount of money in their product, and I think there is nothing wrong with us expecting them to invest a bit of time and resources keeping that product current for a reasonable amount of time. And I don't think 5 or 6 years is a reasonable amount of time, considering the price tag.
Right now, I'm running fine in Windows 10, and hopefully it will keep doing so. But I don't like being outside the support loop, so to speak. An upgrade or patch for Sonar or Windows could cause problems with the drivers, at some point, and who do VS 700 owners turn to if that happens? I realize that may be unlikely, but I didn't invest in this system with the expectation I'd be playing the odds when it came to technical support. I paid the money, in part, because I expected to be supported in its use by the company that built it. I didn't pay thousands of dollars so that problems would be possible but "unlikely".
As for sticking it out with Windows 7 -- well, yes I could. I'd be rolling back to Windows 7 right now if I had no other option, and I'd be able to keep working. But I've noticed a nice little increase in Sonar's performance using Windows 10. Why should I have to deny myself that improvement simply because Roland has orphaned their own product? I want to enjoy Windows 10's improvements and features as much as anyone else, not get stuck in an OS two generations out of date.
Roland's decision is cold-blooded but I do understand it. They no longer want to devote resources to a product they have discontinued, with a smallish user based (I'm guessing), and with ties to a company they are no longer affiliated with. Its pragmatic, and they have the right to do whatever they want with their company. But its also bad customer relations, and I think its an act of bad faith - I put my faith in their product and their support, and gave them a fair hunk of money for the priveledge, and they cut me loose before I think they should have.
That probably can't be fixed, and I'd be surpised if any sort of pressue from VS 700 owners would make a difference. I'll keep soldiering on with the VS 700, because it is a great piece of hardware, and it the best sounding and most enjoyabvle system I've ever owned. But I defintely know that Roland will never get another penny of my money again.