It only is an illustration of the male-centric world we live in. The male Pokemon must be superior simply because they are male, and men cannot like feminine things (though women can like masculine things) because feminine things are inherintly bad and only for women. Masculine things are good and fine for either men or women. So a man having female Pokemon is gross and icky and dumb.
There are so many.
In response the only time I specifically want a male Pokemon is when I need it for an evolution or I like the male look better (most Pokemon with a mustache have a bigger mustache as male, so I will go for the male, because I love mustaches, and the bigger the better. Male Jellicent has a mustache so I used that, but female Frillish was cuter to me so I made sure my most recently visited page in the Pokedex for Frillish was female so it would show as that when I pass through... stuff like that).
"Earth is a silly place. Half the world has no clean water. And the other half has so much, they poo in it."
Jellicent is the only time I refuse a female pokemon. It's disgusting.
Yeah, I guess that would be a reasonable exception, when the forms are so incredibly and noticeably different that you can actually cite design preference for one, but there are so few Pokemon that applies so.
My NIDOKING brings all the boys to the yard: http://goo.gl/ExAoe