Did he do the stupid voices back then too? That has to be his biggest downfall, the stupid voices and the ridiculously stupid characters he plays. I can watch a few of his movies like Happy Gilmore, The Wedding Singer, and Big Daddy. He's playing relatively normal people in those movies, with normal of course being relative to the rest of his career (yes, Happy Gilmore is normal compared to playing the devil, a retarded southerner, or his own twin sister).
If he just stayed away from so many characters maybe people would have a higher opinion of him. Then again, the need to play all of those types probably says a lot about his talent level (its low).