I enjoyed the finale because it shows that you need to fight for your dreams and that sometimes you may be forced to give up what (or someone) you really care about to get there. In this way, this episode reflects the reality we live in perfectly. And the fact that somebody is fed up with some of the characters, say Rachael, doesn't change the fact this epi had a great message. Life's tough and only a lucky few get the chance to fulfill their dreams.
I also think it ended on a positive note. Take Kurt, he didn't get to NYADA but seemed pretty happy for Rachael as did the rest of the characters in the railway station scene. So, to my mind, people should learn to be happy for other peoples' successes.