So, one of the "benefits" of being unemployed is that I have a lot of time to catch up on TV shows via Hulu. I'll probably write about a few of them in the next few days/weeks but today, I'm talking about "Glee".
It seems Fox has two kinds of sitcoms. Ones that are excellent if somewhat twisted, and ones that are just bad. Glee falls into the latter category. There's nothing good about it. Seriously. Nothing. The characters are bad stereotypes, which is somewhat excusable in the students, as my memories of High School make me think that most of us were, in fact, bad stereotypes at that age. But the adults are so one-dimensional and formulaic as to be unwatchable. The music is entertaining, but not terribly creative, and the over use of auto-tune is painful. So, as a show, it's about what you'd expect for a pop-culture, lowest common denominator sort of sitcom.
But the worst thing, to me, is the stereotypes. They make no attempt whatsoever to break the molds that we've seen a million times before. The one gay character is flamboyant, fashion-forward, and terribly effeminate. The one handicapped character is good natured and self-effacing, The popular kids are football players or cheerleaders and they're all stupid. The Jewish girl is a self-absorbed, power-hungry princess. People who believe in chastity are hypocrites and bigots. The list goes on and on. There's no imagination involved at all.
Compare it to King of the Hill, which could be full of unquestioned stereotypes. In fact, it practically begs to be and, in the early seasons the characters were much flatter. But as the characters developed it turned out that Hank was more open minded than even he would admit. Dale was a better parent and husband than most of us are in real life.
I know people will disagree with me, but after watching almost all of the first season, I can say "Glee" isn't worth my time. (Which is saying something, since the job market indicates my time isn't worth all that much.)
A conclusion I reached about Glee early on was that it has intentionally turned up the saturation on the stereotypes. Prime evidence that this is the case: The cheerleaders all always wear their cheerleading outfits.
What you've identified as a flaw of the show is that the characters have no growth potential. If you're looking for growth potential, you're looking at the wrong show. Glee is designed to be as you've described, not accidentally as a result of bad writing -- which is one of its joys.
That said, if you prefer shows that allow for character growth over a show like this, that's your prerogative. The general viewing audience, also having participated in the cancellation of shows like "Popular" (very similar archetypes), would tend to agree with you. But consider that the show is yet an exemplary instance of its type, rather than one that aims at something you're expecting it to be, a target which it would purposefully fail to hit. It's like saying that a cop drama fails dismally at situational comedy -- the shows are very different in concept.
If anything, the most recent episode had too much drama and character development (Mr. Schu discovering his wife wan't having the baby), when it's supposed to be zany. A show in this genre should really have done something like devised a way where Mr. Schu would want to embrace the notion of adopting Quinn's baby.
The failing here is that the show dipped into the type of drama you're looking for and it would fail to ever deliver because that's not the nature of the show.
Anyway... Feel free to dislike Glee without fear of getting attached to it. My prediction is that it's not going to see a return after it gets killed in only one season. Quirky, misunderstood stereotype-driven shows like this don't stand a chance on their own. Combined with the cancellation history of musical-like TV shows (Cop Rock?), this one is pretty well doomed.