@jnp809. It is so subjective! I think it's very impressive that you got interviews at both Yale and Columbia. I got interviewed by some of the schools you got rejected from, but did not get interviewed by Yale, so who knows what goes on behind closed doors.
I know it's technically illegal to have quotas in a lot of states, but I think your background as a person partially plays into their decisions. I know UCLA's program is lacking in female writers, so in addition to liking my writing or whatever else they saw in me, the fact that I am female may have played a part in my ultimate acceptance. They might have interviewed a male candidate who was just as impressive that they may have admitted instead of me if the situation had been reversed. Point being, it's out of our control, and I know it's so easy to jump into that "what did I do wrong?" thinking, but the truth is that no one who showed up, tried their best and then got rejected did anything wrong. The only way to have done something wrong would have been to not show up or to tell them that you hate their school and writing plays... which I am sure no one who spent the time carefully applying to these schools did.
While I think playwriting MFA programs are great for those who want to attend them (me being one of those people), it does often seem challenging and almost meaningless to mix creativity with a systemic and competitive process. If we were all applying to business school, I might understand that I did not get into a program that someone else got into because my GMAT score was lower than theirs. Of course there is a level of subjectivity to everything in this world, business is a lot about personality, and test scores aren't everything, but I do believe the subjectivity factor generally increases in creative fields. So in a hypothetical sense it suddenly becomes one person writing comedic heightened realism about teenage girls living on the moon competing against someone else who wrote a realistic drama about the civil war and maybe the person reading the two plays so happened to be way more interested in serious war plays than zany poetic plays about teenage girls... so which candidate is really more "qualified" in that sense? The great thing about creative fields though is that everyone ends up where is best for them... even if that place isn't in grad school quite yet.
I got rejected from Brooklyn College today too, so now I’ve heard from everywhere. Yay!