A lot of people just don't find BBT funny, which is a reasonable opinion to have, but they both manage to poke fun at their respective sub-cultures.
The IT crowd subculture is generic "IT support." The subculture of BBT is the pseudo-intellectual crowd who took biology 101 and are now experts in everything "science."
As I said, I would never begrudge anyone who doesn't find BBT funny (it rarely is!) but let's not pretend that IT crowd is somehow magically different, it is just better written.
That's just the thing though, people can't tell the difference and I don't think the show even knows it, having all those characters around who apparently know very little about science but who are being portrayed as prodigies.
I learned about this show when friends told me "hey, you're a science type, you'll love BBT. It's so funny and clever!"
Then I watched it and it wasn't clever at all. But it is designed to look as if it is.
When will we get our own show where a vim user and an emacs user, both contributors to the linux kernel, have to share an apartment next door from a frontend web developer writing ruby in SublimeText?
BBT isn't just "not funny", it's actually rather obnoxious.