It depends on the sport. Things like tennis, golf, curling, soccer - not sure why but I find the women's games entertaining even if they would get destroyed by amateur men.
But other sports the quality just isn't there. I could never watch professional women's hockey even if it is entertaining in the Olympics when Canada plays the USA. I guess it's not the fact that a Minor Midget AA team would beat them, the sport is just not as entertaining when women play it. I think baseball would be the same way. The WNBA is that way (haven't tried to watch it in forever though).