You're posing nothing more or less than an opinion, and genre definitions are not something that are objectively and indefinately determinable in every individual case worth disputing over. If you want to use the precious metal-archives as some kind of basis for substantiating an opinion on what may or may not be metal, then consider this; if metal as a genre can be determined upon a band independent of what opinion may bias one towards, then why do they quite clearly discuss the difficulties that can be encountered when trying to establish whether a band is metal or not? For example, the rather blurred line between grindcore and deathgrind/brutal deathgrind?? In cases like this, a band's metal status must be decided-upon on an opinionated, case-by-case basis. Two things (above others) about your supposed objective declaration that Mudvayne aren't metal that stand-out to me; Your qualifications and bias. Its quite clear that you dont like Mudvayne, but what's even clearer is that whatever objective view you claim to have isn't that at all. Its quite obvious with your language that you just can't help yourself but relish subjectively bashing them behind a mask of 'fact'. Furthermore, you openly acknowledge that you haven't heard any of the songs quoted by Sunlapse. In fact, i'd venture saying that you've probably only heard Dig and maybe Death Blooms. Considering the diversity of Mudvayne's material, you're in absolutely no position to pass much judgement at all on their music or lyrics (which you evidently haven't read much of or payed attention to), much less with the idiotic pretense that your evaluation is some kind of fact applicable to all their music.
Secondly, your description of the music. I'm not even going to entertain whether or not anything you said is correct or not, because as explained, you're in no position yet to substantiate any of it beyond a song or two. But regardless of this, you're going on about detuned powerchord riffs, funky bass lines, catchy choruses, little to no intricate musicianship.........simply, there are a great many (underground or otherwise) 'metal' bands that incorporate some or all of the above, and many of those don't even do it nearly as well or as complex as Mudvayne do. Gore metal and deathgrind bands, as well as more conventional metal bands use many powerchord oriented riffs with extreme detuning. Even more metal bands of all genres use catchy choruses, either with melodic clean vocals or catchy rhythmic lyric/vocal enunciation.....and hooks. Hooks, ha, theres hardly a metal band out there that doesn't use obvious hooks. Your tailoring of the term to point towards commerciality is just an irrelevant spectral transitive.
Just.....gah. I can't be bothered with people like you Necro Joe. Arguing with you is pointless, because even if someone provides some conclusive argument to refute your own, you're of the type who's stuck-up arrogance forbids humility and concession, and instead you just keep going at it like a dog humping a leg; the leg ain't a dog and you know it, but you just go at it anyway right?