I’m pretty cynical when it comes to reviews and reviewers, so my opinion on why it’s getting bad reviews maybe isn’t worth much.
It has been getting as many good reviews as bad ones, though. Metacritic has it 68, and the indie / fan blogs are split roughly 2 to 1 on rating it 70 or better.
Their self-titled debut was “universally acclaimed” on the metacritic rating, and the follow-up (Exploding Head) received more or less the same adoration. The debut benefitted from the shock/freshness factor, and the follow up simply doubled down (tripled down) on that bet. After that, the ratings have been steadily heading downwards.
I’ve just finished relistening to their back catalogue in order, and I no longer feel that the first album is superior to the third (Worship) nor even fourth (Transfixiation). Exploding Head and Pinned slightly edge the others, but they’re all great, including the On The Wall EP.