The male carries the pollen that pollinates the female, and it's the pollination that makes new seed. Just like with people -- the female carries the egg, the male carries the sperm and you have to put them together to make a new generation. Same with the plant. The female carries the bud, the male carries the pollen and you have to put them together to make a new generation.
So if you want to breed plants in the future and want to start developing your own seed inventory, then males are important to you.
If you're just growing to sell, then you don't want any seeds in the bud because customers don't like that. They like their bud to stay virginal. So you don't want a male anywhere near those females.
But if you're growing to smoke it yourself, and don't mind taking out seeds, then it probably doesn't matter all that much. Back in the day, all weed had seeds in it, and getting them out before rolling was just part of the ritual.
On it's own, the male doesn't have a use, as it doesn't contain the THC that the female does.
Hope that helps!