It's long term renters that increase the probability of issues/squatting/ill-maintenance cropping up, and generally start a long term degradation of the neighborhood. Long term renters also seem to buy ridiculously overpowered audio systems, and run them in such a way that one can hear the thump-thump bass, a block away. Not to mention they often pack like sardines into a place, and then you have 4 or 5 autos per residence.
"How dare those uncouth young people not abide by my arbitrary standards of class that I expect the neighborhood to meet"
I don't see why people are so bothered by what other people do. Any normal community is going to have people doing things and some of those things make noise, smell or sound.