I don't have any problems with your logic. I do note, however, that you are only having HALF the discussion. Our ability to throw up a shield block, or do anything useful, really... depends on having rage, which depends on us taking damage. One unpleasant scenario you did not describe is:
miss, dodge, parry, dodge, ..ooops, not enough rage for shield block/shield slam...etc...tank gets crushed, or someone pulls because they're right on your ass in threat and they didn't expect you to stop kicking it out...my raid leader and I have both moved away from heavy avoidance builds not because it was tough on the healers...but because people were getting threat capped. if you don't take damage, your auto-attack is not going to allow you to generate the threat you need to hold off 1200-1500 dps.