If you want to make fun of MS Windows stability issues, you bring up the Blue Screen of Death (BSOD, although, to be honest, you hardly see them these days). When the Windows folks want to fire back, they point at the spinning beach ball that indicates an unresponsive Mac application. So these two design elements have negative connotations prominent enough that other system vendors should not want to copy them.

Today on the train the person next to me was using a Samsung Windows Mobile phone which displayed a spinning beach ball. In the four Windows logo colours. Weird.

PS: I also saw a guy with an iPhone and an iPod touch.