Don't all knits look like "schmutters" (what a great word) after no time at all though? I haven't found this problem to be unique to Anthro or FP. On the flip side, I have had great success with Anthro woven tops, so if I could afford them, they would have a much more prominent place in my wardrobe.
I find myself either loving or loathing individual items on FP. Some of the stuff is just outlandish and wacky, but other items put me over the moon.
As for people my age being able to afford it or not: I am never going to pass judgment on a situation I know nothing about, but in the case of many people I whose situations I DO know, they aren't necessarily "doing well" or able to afford what they buy. They are just careless with money. Sorry if that sounds obnoxious but I have seen a lot more of that going around than I would like. I can't say anything about it because it's not my place, but sometimes I REALLY want to.
Anyway, I think FP definitely offers a very unique look so while there may be a lot of other places for rich and/or irresponsible 20somethings to shop, they are never going to get the FP look from any other brand.