Because they have everything they need in that area charities feed them and give them clothes, The drug dealers are there as much as the charities are. Plus they can come and go on the PATH since that railroad barely ever enforces fare jumping. Also except for the hour's of weekday rush hour they usually are allowed free rein over penn. Now as far as new york Penn and Newark goes new York penn has a even worse homeless issue. That mainly because of all the methadone clinics