I honestly don't know. I don't really pay attention to stuff like that. Didn't MM and Trent have a falling out around then? Like, "Starfuckers Inc" and all that? Wait, did Trent attack Billy in that video? He attacked a bunch of musicians didn't ? Ah, I really don't remember. I might be making this up.
Adore sounds nothing like OK Computer. Downward Spiral..... maybe, but this is half a decade later. I really just think that the NIN/MM "thing" was in at the time. But also losing a drummer lead them to dabble in drum machines... and then keyboards... etc. It was an easy point in their career to try something new since they had a reason to try something new.
I'm surprised you don't like it tho. Most NIN fans who read Pitchfork every day seem to call it the one SP album they like.