Abercrombie and Fitch have had their well-known travails in this area; one could make a case that a lot of their clothes were at least marketed to teenagers with their own income, although marketing clothes with unclothed models is not a strategy that readily occurs to an average shopper.
Still, they're hardly the only ones, and any trip to a mall or a tourist souvenir shop will furnish one with anecdotes to last until crotchety old age. Yes, yes, then of course I don't have to dress my kids like that, who am I to judge, etc. etc. [/lileksvoice]
This happens to be good advice - so good, in fact, that I don't feel in the least uncomfortable about offering it back - you don't have to dress your kids like that either. Should I have a child I plan to keep this excellent advice. I'll not see her wearing such things as "bitch," "sexy," "naughty," or "hot stuff" across her pre-teen rumpus. And if he's a boy, neither will he be sporting t-shirts such as I saw on a recent trip to Sears:
1. "Now Hiring - Person to do my homework and house chores. Must also sit in detention for me. Dial 555-LAZY."
2. "Do you mind? I'm trying to ignore you."
3. "Warning - Kid Has Attitude. Stay back 50 feet."
Yup, all wholesome ideals any kid should aspire to.
No one has to dress a kid in this stuff, but we have to put up with that kid seeing them on his peers and wondering why he isn't enough of a delinquent to be cool like them. Those pressures are great enough without the implied approval of sloth and incivility. Kids have always had attitude - but it's a lot harder to grow out of it when the parents are buying shirts that support staying the way they are. Warning? We shouldn't have to be warned about them - they need to be warned to knock it off. (Then again, one of the other slogans was: "Go ahead and send me to my room, I've got pizza and video games!")
So, young fogey that I am, I'm pretty sure that dressing kids like this is a bad idea. Clothes like this undercut a parent's authority - it's like a note to disregard whatever they say about manners, hard work, or discipline. Will it turn them into degenerate junkies or Klan bikers or something? No, and I'm not staking out that kind of territory. The changes are subtle. You don't get a long time at all to establish sound habits of mind and body in a child. Letting that foundation crack early robs a child of strength that he will need later. A t-shirt is a laughing matter; a kid who blows off unpleasant tasks is more serious. The kid may do it anyway, but he ought to at least know better while he's doing it - he shouldn't feel proud of it, nor scoff at anyone who's trying to help him become an adult someday.