I think you guys are making matters a lot more complicated than they are, in the "why do people hate COB"-matter. If someone hates the vocals in COB, he likely hates 99,9% of vocals in the whole extreme metal genre (and many people who like Pantera dislike COB, even though they have 90% similar vocals) anyway. And I don't think that was the point anyway, but the fact, that many people dislike/ laugh at COB even though they listen to a lot of same kind of music. The answer is plain simple: people hate COB because COB is mainstream, same goes with all the popular bands (except the legendary ones, which are "not allowed to hate"). The more a band is liked, the more it's disliked, the same goes with all genres; hc-blues people think, that Gary Moore's mainstream "blues" is shit, black metal people think, that Dimmu Borgir, COF etc. are shit (even truly devoted bands like Watain are starting to get mainstream-hate nowadays), and so on. Of course metal has always been supposed to be a statement against commerciality etc. so in metal genre the anti-mainstream-attitude is even stronger than elsewhere.
Also, on the topic of COB's "special" melodies and incredible talent; sure COB has a lot of good, great, even incredible melodies, but I don't see anything special in them compared to thousands of other bands, and hundreds of thousands of other melodies. Some melodies are good, some are not, I don't see "speciality". Same with the talent, world is full of talented bands, I don't see why anyone should respect COB for being "super-talented" or something. I have approximately zero respect for Dream Theater even though they are techically talented as fuck, because I think they have zero musical talent, which is totally based on opinion, it's completely legit for one to say he doesn't see any musical talent (aka ability to make good songs) in COB, and the other way around of course.
the worst is when u talk to kids about metal, and they ask me my fav band and i go "COB" then they give this look of EHhhhhhhhhhhh on their face, like they maybe heard one song before, then they go, you heard of *insert standard scene metalcore band here*
it always ends in me going WTF IS WRONG WITH YOU
You know, I get the same wtf is wrong with you-vibe from people like you.
the worst is when u talk to kids about metal...