I don't think we call tell they hate them as main characters because the main creator of the show, Tom Mcgillis is gay himself. Tom the fashin blogger is confrimed gay and he is based on Tom Mcgillis himself. Jaques is confrimed gay as well. Sanders confrimed by her voice actress is a lesbian. Both Sanders and Jaques were main characters.
besides, even though only three characters confrimed to be gay there is decent gay subtext in the show even in the striaght people, thing that really turn them to bisexual. Good example are Noah, Owen, Alejandro, Katie and Sadie, Chris, Chef, Topher. Shawn and Dawn themself can be seen as pansexuals.
the reason the LGBT subject in the show is more in the subtext instead of confermation is maybe the reasulf of CN, They forced multiple times on fresh to do what they want. They forced them to breack up Gwen and Trent. They forced them at least two times to replace female finalist with a guy just to avoide all female finale and they forced them to not do the romance between Tom and Jaques. I wont be suprised that everytime fresh wanted to introtude LGBT character CN corfed them to scrapped this idea. all fresh could do is keep it in the subtext.