Why thank you M. Le Pew Frits.
To be more specific, I actually find the average intelligence of "tweeps" a little higher than most places on the net. Well, mine anyway. I think it's because you're not obliged to friend everyone you know after the style of Facebook, and on the flip side you can track the utterances of hyper-intelligent non-acquaintances without seeming like a stalker.
There's a fair chunk of everyone's personal network who simply don't get the internet.