This is me as a Magical Girl destroying a Rounded Corner Monster. I'm probably too old to be a magical girl now that I'm in my twenties. Oh well.
I hate rounded corners. I once worked for a company whose designer had unfortunately learned how to put rounded corners on elements on a web page by using fleets of bastardized bold tags. The engineer who showed her this technique didn't see any issue with it because "Google uses it!" And, if Google uses it, it's gotta be great, right? (Like iframes!
I tried to get us to use CSS3 rounded corners, which would be significantly lighter but wouldn't work on IE. IE users would just get square corners. But marketing/design/everyone's brother demanded that the pages look exactly alike from browser to browser, and I never managed to convince them all that progressive enhancement is acceptable at the same time.
Point is, I've come to hate the little bastards as design elements.