And what I'm saying is, why do you think a bunch of nothing background characters are any better? If you want waifus, there are bound to be plenty off Earth that actually have things going for them beyond being generic "literal who" high school girls.
Hekapoo comes to mind as an example of someone anons want to waifu who actually has a personality and established role.
Janna actually had a bit of a dynamic with Marco in that he's annoyed with her and she likes being weird around him, which happened in both of her major appearances. We also got more insight into her interests in occult stuff and creepy/extradimensional stuff.
You can't say what kind of role any of the "waifus" besides Brittney had re: Star and Marco, because there wasn't really one, or what they liked beyond the most genetic "well they wear cheerleading uniforms so they're probably into that."
It's definitely true Janna didn't have much of a role in the first season, but there was still a personality there, which was why she got the increased role in the first place-- the crew found her fun to write.
If you really just want to look at the blandest background characters imaginable, then watch School Spirit on repeat 100 times or just stare at a picture of them forever. Because they never did anything in the show beyond that and so I don't see what the big deal not including them would be. They've done as much as they were ever going to do.