First of all, the movie industry is a bit backwards, still, and that manifests it self to this particular question in a couple of ways -
Physical attractiveness is still a much more dominant requirement for female roles/actors than male roles/actors. A comic relief character often needs to look funny or fits a mock-able stereotype. It's much easier for a male actor who looks goofy to have an extended career than a female one, so there is a larger pool of readily available talent for those kinds of roles.
Major studios, themselves, are more interested in making money than the pure artistry, in general, so they like to keep recycling things that have made money for them. Goofy male sidekick tends to go over well? They're going to greenlight projects with that, just like they like to do "reboots" of popular stories and sequels, or movies that fit a particular formula. If they are nervous about general box-office appeal, they might even push for the addition of that element into a movie.
A lot of time the comedy of the comic relief character is, to a large degree, laughing AT that character. It's a bit safer and more comfortable, agree with it or not, to laugh at a male character without running into accusations of sexism.
Finally, while less common, those kids of roles do exist. You see them all the time in movies that are more dominated by female characters because their companions who they interact with are going to be more heavily female-populated. Even in more traditionally male-led casts, you will see some good ones. Here's a few I can think of -
Joan Cusak's role as John Cusak's office manager for his assassination business in Grosse Pointe Blank.
Jennifer Lawrence's ditsy, money-grubbing bored housewife role in American Hustle.
Marisa Tomei as Mona Lisa Vito, the girlfriend of Joe Pesci's character in My Cousin Vinny.
Whoopi Goldberg as the psychic in Ghost
The title-specific role of Owen's mother in the movie Throw Mamma From the Train.
I'm sure there are many others that people can think of. But, sure, there are definitely more male roles for that, but that's true for almost any character type this isn't exclusively female.