I don't agree with your assessment about the original. Literally I watched the movie again 2 days ago and I think many peope have some rose tint to their glasses. One of the reasons it's great is because it isn't self aware. It's legitimately trying to be a good movie and Swayze is playing his role with 100% conviction. That's actually one of the reasons it works because Swayze is still a charismatic, likable lead.
I agree that Gyllenhal is solid. I was actually an unfiltered Jake-Hater until Nightcrawler and the son of a bitch won me overbetween that and a couple other performances. He finds the perfect Zen for this role. The scene of him driving the bikers he just crushed to the hospital is pretty awesome.
Your last paragraph mentions fun, and that's really the only important thing here. If somebody goes into this movie sharpening their knives it can be eviscerated pretty easily. It's one of the movies thats sort of "critic-proof", like spoofy comedies or big budget action. It makes no attempt to win you over with any "serious film" elements. It's only goal is entertainment as long as, just like the original, you leave all sense of seriousness at the door.
It doesn't surprise me that the movie divides people. It's a "works for you or doesnt" kind of movie. What I am surprised about is how many people are propping up the original as something that it isn't. Because the original is absolute glorious trash.