> [The C rule was rejected for C++ because it] could inhibit useful optimizations

If be curious if these are the sorts of optimizations I would find useful to the point where I would be happy to pay the price of this annoying new behaviour.

Or are they just the sorts of optimizations that a compiler writer finds useful who is engaged in a multi year career-defining pissing contest with a competing team?

Don't get me wrong, I have myself engaged in a multi year career-defining pissing contest with a competing team. It's fun. But let's not kid ourselves that it's for the users' sake.