I think this talk of "this class can do this, 3 to 4 times a fight, but i can't" is kind of off

Pally's build holy power, if they self heal, it's a massive dps loss
Rogues build combo points, and if they spend them on anything but their best rotation, it's a massive dps loss
Hunters can blow focus, but at a dps loss in many cases.
Mages can do various things...all resulting in dps loss, and then they have the token oh sh*t key for ice block...
Priests get a pain suppression or wings, but they don't get it once a min or anything
Shams are different for sure, those totems get put up constantly...but are they really necessary (much like your lock shard question...do they even matter)

Other classes have similar questions of what to use. 1 Cold blood is a decent dps hit, but an overall dps increase for the fight...nothing too huge, it's a crit and maybe a couple more muts, but that's all.

I think as it currently stands, they are aren't powerful enough to warrant them regening 1 per minute, but the balance between how many you can get while in a fight, and how much they increase an ability needs to be very carefully considered.