Well, it happens with free software as well. See the Gnome 3 uproar. Yes, you can keep using the old version until bit rot takes it. And yes, you can fork it -- good luck with that.

Please forgive me, but I'm about to focus on your example, rather than addressing your larger point.

I know that that's generally poor form, and admittedly a bit impolite, and I apologize..

I was just struck by your example - The Gnome 3 changes seem like a very good argument AGAINST your position!

Many people did not like the UI changes which were brought in Gnome 3, as you mention. After it was released, a group of users who were not fond of the change release MATE which is still very much in development, and (reasonably) widely used. It's included with many major distributions, and very straightforward.

Another group (Cinnamon) originally forked the Gnome2 shell, and then later forked the Gnome3 shell and window manager, in order to restore a more Gnome2 like UI.

In general, I agree that maintaining your own fork is a lot work, and likely not worth it in many cases..

But if it's something that you care about enough to throw hours at it, the option remains open.. And that option is taken more often than you might suspect!