I guess I'm not understanding your complaint then.
Here is some footage of how I play the game (this is not my footage, just similar to my style of playing the game), and I dont really see a "glued effect."
Then again, I play realistically and rarely do 360's (not really a big street trick unless you're Chris Cole)...for example, a 360 kickflip 360 (known as a big flip) is rarely ever done in real life and I never do it in game. I can imagine that it probably looks bad because the board has to be spinning on the same exact axis as the skater like they were teathered together.
I'm not trying to play the holier than thou card on anybody who enjoys this game, I just play it as realistically as possible and rarely do I see things look unnatural and wonky.