Problem is not that it was magical, it's that it took itself too seriously to explain why it wasn't magical at first and then they threw logic out the window.
At first they explained the electromagnetism of the island, that made it special, and why Dharma was there, and why the plane crashed, etc. All that was great. Even going as far as the Constant with Desmond was pretty brilliant, out there, but brilliant and awesome.
Then the time travel, which was crazy already, and that donkey wheel, a little ridiciulous, but OK...
But then the origin of the smoke monster? And good vs. evil? And two brothers fighting over their mom? And it turns out all this shit was over some mommy issues? And then reviving Locke just to keep the actor in the show? I mean, too much stupid stuff too soon. It ruined all the stuff that made the early seasons great.
And stuff also contradicts each other. One episode, Ben "summons" the smoke monster somehow to kill soldiers. How did he do that if the smoke monster was just this rogue dude?
I mean, I could go on for hours and we already did this way back when. The difference between this and Dexter was that this was still entertaining and suspenseful somehow even with all the bullshit. Characters stay mostly true to themselves too. But the plot was just ridiculous towards the end.