Comparing it to the men's division is the equivalent of saying the lightweight division sucks because heavyweights would maul them. They're different divisions, they are split up for a reason. What matters is relativity. The women's 135 can be exciting without needing to be better athletically than the men's 135, for the same reason flyweight can be great even if Nick Diaz probably took their lunch money in school. By your argument, you would only watch heavyweight or light heavyweight because they represent the biggest and baddest gorillas in the jungle.
If you can watch multiple men's divisions and respect the weight class separations, then you can watch the women and respect the sex separations without complaining that the men are more athletic or more powerful. What makes the UFC great is finding out who the best in the world are in their respective divisions. It's about relativity. Yes, maybe joe-blow unranked bellator fighter can dominate a highly-respected female fighter. Who cares? Who cares any more than saying Cain can kill Mighty Mouse? All I care about is how good are you respective to your peers. Joanna vs. Claudia II was outstanding and full of tension, because you knew you were watching the two best in the division going at it, both trying to impose polar opposite gameplans. If you follow the division like any other division and come to know the fighters, it can be just as enjoyable as the other divisions.
Women are half the population in the world. If you're not excited to know who the best in the world are for half the population on Earth, then you're selling yourself short of some great fights, narratives, personalities and expressions of technical abilities.