maybe guys are more competitive so they practice more to be the best. as guys have bigger hands they probably have better reach.
but on the othere hand, guys fingers are 'fatter' so girls can probably be more articulate.
and at the end of the day these are only trends not rules. there are plenty of guys with small hand s and girls with larege ones.
and anyway what defines better. being able to play faster, or more complicated. you cant really say that as everyone views different things as more important. some like speed, some like catchy riffs, some like harmonically interestin ideas. watever floats your boat.
at the end of the day iot aint inportant, look at guitarests as muscisions and ingor their sex. generally a way to view things in life.
edit; above coment obviosly doesnt apply when it comes to relationships, sex etc