Yes, I agree with Alan's answer that women are quite able to perform at a high level in gymnastics, so tricking is not a problem for them physically.
And I agree with others that there are generally more men in martial arts than women, so that is a part of the explanation.
Then there's the fact that there really aren't many "tricking" classes offered, period. There are lots of gymnastics and cheerleading classes, however. In many cases, the only place you'll find tricking instruction is on youtube.
Lastly, gymnastics and cheerleading are culturally more social than tricking is. According to psychology and sociology, women emphasize relationships and being socially connected more than men do. Guys, on the other hand, care more about the action itself, how it makes them feel or look, rather than whether it also leads to forming closer bonds with their friends. And so since tricking typically doesn't have many people in the class, or even any class at all (just youtube videos), guys more than girls get interested in it.
The way ahead if tricking is to become more balanced between the two sexes is to make tricking instruction more available, more social, safer / more professional, and less seen as a martial arts activity and more like a "performance" activity similar to contemporary wushu kung-fu, gymnastics, or modern dance.