It's not as difficult to get into a private art college as everyone likes to pretend.
Getting in is relatively easy. Staying in is what's hard.
When I was an admissions counselor, 80% of the students who came in for advice already had a portfolio that was acceptable to be admitted.
But I rarely told them that.
I would critique their work, pushing them to work harder to improve, and sending them off to rework their portfolios. Why? Because art schools want dedicated people.
The student might go home after that admissions visit and decide it's too hard, or they aren't good enough, or they can't bear to have anyone look at and critique their work. Well, that's not the student we wanted.
Art school itself is hard and stressful. Students are pushed to their limits, physically, emotionally, creatively. Teaching technical skills is easy; teaching students to push through their barriers is not.
Art Schools want fearless students, artists who are unafraid of their talents, and also unafraid of their weaknesses. Your portfolio doesn't need to be perfect, but it should be fearless.
Creating an atmosphere in admissions that makes the school seem really hard to get into is helpful for weeding out the students who do not yet have the mindset for a demanding program.
Good schools want dedicated students who will be successful after they graduate, and as alumni, will make their college look good. They want students who are ready to work hard and slog through the tough times, spending the entire 4 years (and 4 years' worth of tuition) at their school.
Work hard on your portfolio. The hardest you've ever worked before. It's good practice. It shows something about you as an artist. And last but not least, the stronger the portfolio, the more $$ offered in financial aid.