I could be mistaken, but didn't bears recieve a notable increase to their Armor on PTR? So the whole damage vs. survivability context there is a bit skewed if it is not taking into account the survival increases coming as well.
Personally, I'm willing to give up some of my damage (although there is no white damage nerf, so it's a tad less) for a notable bump in armor.
That said, I do feel like the Feral Bear nerf is a bit on the lazy side and missing the subtleties of how Bear DPS works. There are certain scenarios where Bear DPS is extremely high and others where it is high but not 20% higher than other tanks.
A flat decrease is pretty short-sighted. I would have liked to see some more precision in these changes.
First off, 20% is too convinient of a number to be precise at all. It's a number picked from thin air. Nobody sat down and figued out exactly how much Bears should have been brought down compared to other tanks. Perhaps it should have been 17%, maybe it should have been 12.5%, or maybe 8.541%--but '20%' is just sticking one's finger up in the air and making something up. Blizzard has enough data to do better than this.
Secondly, it should be aimed more specifically at certain things. Could Mangle serve to be reduced? Yeah, probably. It hits really hard. Did Lacerate need to be reduced when it's already one of our weakest abilities and only contributes between 1-3% of our damage? Highly doubtful. If anything, Lacerate should have been buffed a bit in damage if you ask me. Did Thrash need to be changed at all? Kinda doubtful.
My guess is that, in reality, any downward adjustment for Bears should have been in the realm of 5-10% and Mangle and Maul should have bore almost all the weight of the change.
A 20% flat change is probably going to have to be adjusted later--my hunch is that it will end up bringing Druids too low in addition to making Lacerate even less attractive than it already is. (I find it strange that just a few days ago they talked about wanting to make Haste attractive for Bears via Lacerate scaling, which is pretty silly considering how poor Lacerate is right now.)
For Warriors, Revenge certainly needs to be buffed. A lot.