Sorry, but frankly your information is a bunch of baloney.
News flash: Those few people you met were weeded out because they are weed.
What, did you think dental school is a 4-year-long 24/7 party that will hand you a DDS/DMD degree without doing any work just because you paid the tuition money? I don't care who you are, you will flunk out of ANY dental school if that's your attitude.
NYU graduates ~300 students EVERY YEAR. They DO NOT "knock down" their class size to "100". My sister's class (Class of 2000) graduated 320 dentists. She is in her 3rd year of private practice after doing a 1-year GPR and now she owns her own office.
"weeding out" students to "make money" makes NO sense. It makes sense for a school to keep a student for all 4 years, collect the entire $250,000 bill from the student, and on top of that have each student bring in about $15,000 worth of fees collectible from rendering patient treatment. A school LOSES money if it intentionally "weeds out" students before they can start producing patient fees for the school.
Very few schools receive re-accreditation with zero recommendations (i.e. things that the committee on reaccreditation thinks the school can improve on), and NYU achieved that last year.
Aside from the outrageous cost (which USC is also just as notorious for), NYU is as good as a dental school as any, definitely as good a choice as USC especially for people who prefer a traditional curriculum over a PBL one.