5) Nobody cares about it, so it isn't shown or covered!
Understandable, but also chicken-and-egg, as Hitch pointed out very well. If you have more exposure to something, you absorb knowledge of it, and you can become more emotionally invested in it. Women's cycling is seldom shown, so how can people discover that they're interested in it? Again, as Hitch pointed out, the sports where women are held in the highest esteem by fans are events where the women's events are at the same time as the men's. Ironically, this gives us more chance to directly compare men's and women's performances than there is in cycling, but we don't directly compare the men's and women's performances that often in those sports. Female skiers, biathletes, track and field athletes and even to an extent track cyclists are allowed to be the best at what they do without having to always be compared to the men. Nobody cares that Shelly-Ann Fraser or Mary Keitany can't run as fast as Usain Bolt or Haile Gebreselassie, nobody cares that Magdalena Neuner or Marit Bjørgen can't ski as fast as Emil Hegle Svendsen or Dario Cologna... we compare them to other women, not to the men.