It's cuz' you aren't wearing big ol' football pads underneath them.
And sorry, you gotta wear a jock with those bike shorts (and football pads) or you're gonna "those looks!"
Look at all those football players--tight, tight spandex KNICKERS, for gawd's sake, but they are as all-out macho as any group of guys out there!
But you bicycle dudes do have a one-up on the football guys; you have MUCH nicer looking legs'n buns.
IMHO. . .