I think it's the fact that it's a rarity to see a beautiful girl on a real nice bike that makes these "spots" seem mysoginistic or objective... So I guess it's a bit of a self perpetuating condition... Also this rarity causes fellows who see girls on bike to over-actively search them out as companions or partners as a love of cycling can be seen as a common ground- I know my girl's cycling is a definite plus for me, being able to ride around with your partner is genuinely a great thing to be able to share, so girls, don't be discouraged! Ride your bikes, and just like day-to-day life, ignore the creeps, take the compliments and enjoy that sh*t!
+1