Now you could point out Pages has the same shortcut and same stupid behavior. I agree, but that's what happens when there's a clear market leader.
(Oddly enough, I've been implementing a web-based word processor, and we make paste-and-match (paragraph) style while retaining (character) styles the default. You can't actually do this in Word or Pages — default or not — despite the fact it's what users want 99% of the time. So if I paste some text with an italicized passage, the font changes to match the ambient styling, but the italics remain. When we implemented it, the UX people were flabbergasted -- they assumed it must be impossible because no word-processor does it.)