I don't "hate" his vocals, but I don't listen to Dream Theater for their vocals. Seen them a few times live now, and he is a pretty poor live performer to boot. Saw them support Iron Maiden last year while I lived in Canada, and it was chalk and cheese in terms range, sound and performance. Some albums he's been amazing, like Train of Thought, then others have been very meh. Portnoy and Petrucci made that band, not Labrie.
can't agree at all, i went to both DT's live performances at the Hordern thus far, and LaBrie was fine live. i'm not sticking up for LaBrie, he's not amongst my favourites at all, but i do think he's a technical brilliant singer... and to come back from ruptured vocal chords with the range he does have is pretty excellent imo. he does the job, and helps give the band their identity... i don't think he's out of place in this thread and i can see the appeal of his vocals.
i don't even agree with you about Portnoy and Petrucci making the band. Ruddess and Myung contribute a lot to the band and their sound, and they have just released one of their better albums without Portnoys influence at all. every member of that band is a master of their craft, and to take credit away from other members of the band is doing them a disservice.
i do agree with Corey Taylor and his talents, too. he was the voice of my teenage years. Serj Tankian is another nomination that i like, and would agree with. very interesting vocalist.