Let me put my two cents in on this matter.
Universal has and always will be a business, like Coast has brought up. For better or for worse, Universal is going to make decisions that will bring in the most money. That's what they have done and will always do. They have discovered that using many IPs will draw the crowds and it works. Heck, one of the IPs (Cabin in the Woods) is what's drawing me to very likely fly down to Florida this year. With all of the IPs, at least they're doing some original concepts to help appeal to the more devoted fans like us.
My point is, IP, rehashed, or original (Especially my case since I live down in Hollywood), I still love Halloween Horror Nights. It's a quality event unlike any other. The movie quality sets, the intense scares, and awesome environments put me into another terrifying world where I can escape from everyday life. By being upset about the trivial things that the event is straying away towards, you are forgetting the true purpose of the event: to just have a good time and to enjoy the work the creative team can put together despite the restrictions they have.
In 2010 for Hollywood, I absolutely hated the line-up. It was all repeats and nothing original because they wanted to appeal entirely to the GP. Even though that was the worst year by far for me, I still had a great time with my friends and was able to escape. I am a die-hard fan of HHN. While there are there will always be some things I love more or hate more, I still go regardless because I have learned that I will always enjoy myself. In the meantime, the people who run the event are benefiting from my business while I'm having a good time.
Don't let trivial things you don't like ruin the event for you. Don't let its flaws drag you down and enjoy the event with an open mind.