I don't know where you are hanging out, but most of the teens I know that want to work don't look like that.
Although there are teens that are like your description, your generalization that ALL teens are like this is untrue.
Also, many Mexicans are hardworking and dependable and I have no problem seeing them hired so long as they are LEGAL. Hiring an illegal is against the law, if you are a true conservative you would have respect for the law.
"who wants to hire a teen with bright purple hair, tattoos covering their face, and multiple ear, nose, tongue, lip, and eyebrow piercings, who comes to the interview wearing pants hanging down to their knees and talk like they are a minority LA gang member, even though they are white?"
You're funny. 20 feet away from me is an American kid (Tony) who has more ink on him than mose jailhouse lifers.... he walks around with more hardware stuck through his lips, eyebrows, nostrils etc than the nuts and bolts section of a Home Depot Store. He works 50 hours a week in this job and another 30 hours a week in his second job to support his wife and two kids. Stop stereotyping.