It seems to strongly depend on your career. I can understand it being difficult on a Witch Hunter as you kill things fast, and can potentially quickly run out of targets to keep building on. I play a Black Orc geared for tanking. My 29 DPS at lvl 19 doesn't put things down very quick, so I have time to build.
One of my favorite pasttimes is going out and gathering bestiary unlocks, which involves either finding a large cluster of one type of monster, or soloing a champion. I don't know how it works for other careers, but as a Black Orc, I have negative downtime. I generally switch targets when my current one is at 50%, and throw a taunt or an axe to one of it's buddies, then switch back to finish it off, slowly moving through the herd as I go. The end result is that I always have a target in front of me that I am bashing away at, and is bashing away at me. My massive armor, toughness, and a particular war bellow keep me well into the green on all but the champions.
My issue isn't that I don't build up morale fast enough, it's that I'm sitting there with a nearly full bar waiting for the morale abilities to cool down so I can use them again.
IMO, it's an even trade. I get to use morale abilities more often, it doesn't take you a minute and a half (literally) to kill a normal monster 2 levels below you.
I would debate that the comparison between lvl 40 Tier 4 morale abilities:
BO: 75% Damage reduction for everyone within 65 feet for 10 sec
WH: 25% fewer AP, 50% faster cooldown, 20% more damage on all attacks for 7 sec
IMO, yours is significantly more useful in more situations, but that's my opinion, and could understand disagreement.