Maynard is so overhyped I want to stuff my balls into his mouth so it can start doing something productive. seriously. shit. band. Tool, along with Radiohead, have the worst fans, because they adamantly RAGE on people who don't think they're the greatest shit ever. If it weren't the case I wouldn't be adamantly raging against this tool machine. and for the record, Maynard is a pretentious douchebag who has done some of the shittiest work I can think of (Thirteenth Step, eMotive, Lateralus) and I think his voice is pretty dull.
But that's funny you should mention screaming because half the time anyone mentions how OMFG GOOD maynard is they bring up that stupid 8 minute scream he does. I prefer just about any prog-rock band to tool, i don't dislike prog-rock. i dislike tool. and maynard for that matter.
FACT(since you wanted "facts" as to why my opinion is Tool/Maynard sucks): Thirteenth Step, eMotive, and half of Tool's catelogue, is poo.
Also, Maynard singing real nice over a shitty band doesn't make them a good band.