Because several months ago Sonos released a disastrous update that made a huge mess. They have been struggling to get things working again and have a long way to go.

Topics here thousands of posts long on that subject if you want more details.

I saw that they recently added the facility to go back to S1. WHY don't they also revert to the "old" S2, renaming this failure S3beta until they fix the issues? I don't think replacing the programming department almost entirely is a solution.

Anyway, thanks for the support. I'm starting to think I'm not an idiot...

That is discussed in one or more of the long threads. They looked at it and decided it wasn't a good** option. 

**Not overlooking Sonos Management's iffy definition of good.

… without words…