I can't stand anything on my wrists... officer... er... oh, flash back...
Anyway, I don't like putting a compass or computer on my wrist. Makes it harder to get your arm into BC straps, if I have to reach into some crevice, I will scratch them up if I bump, but probably the most important reason why I don't wear on my wrist is ease of suiting up.
I'll watch some people when they get ready to dive, and it is a 30 minute ritual before they can get in the water. Hook this, clip that, put this on this leg, strap this on that wrist, wrap this here... and on and on...
All my stuff is clipped to my BC. If I toss on my Ranger, and have a reg to breath... the only thing I have to make sure I have is my fins and mask... everything else is in place, and for the compass, it is on a plate with a plastic male clip with a palegic compass.
I also like the retractor slate version we use for our students when teaching classes... If I'm playing dive master... I'll carry that so I can jot notes to the divers.