If you could somehow "stop exploiting UB" they'd just be angry either that you're still exploiting an actual language requirement they don't like and so have decided ought to be excluded or that you followed the rules too literally and obviously the thing they meant ought to happen even though that's not what they actually wrote. It's lose-lose for compiler vendors.
I agree that some of us are unreasonable, but I do recognize that DWIM is not feasible.
I just want compilers to treat UB the same as unspecified behavior, which cannot be assumed away.
Unspecified behavior is defined as the "use of an unspecified value, or other behavior where this International Standard provides two or more possibilities and imposes no further requirements on which is chosen in any instance".
Which (two or more) possibilities should the standard provide for out-of-bounds writes? Note that "do what the hardware does" wouldn't be a good specification because it would either (a) disable all optimizations or (b) be indistinguishable from undefined behavior.
Rust's safe subset doesn't have any UB, but the unsafe Rust can of course cause UB very easily, because the rules in Rust are extremely strict and only the safe Rust gets to have the compiler ensure it doesn't break the rules. So it seems weird for people who work on the compiler guts to be "surprised".
Even if you read any surprise into their messages they wouldn't be surprised that C does something completely unreasonable, they would be surprised that LLVM does something unreasonable (by default).
"LLVM shouldn't miscompile programs" is uncontroversial, but claiming that these miscompilations are somehow "Exploiting Undefined Behaviour" is either incompetent or an attempt to sell your position as something it isn't.