As usual people have deemed something useless or too difficult before knowing hardly anything about the dynamics of the game. I'm sure if you implement the way they intend, it will speed up skill or experience gains. We won't have a good feel for any of this until the game has been out for a little while.
If it really is a case of only debuffing a mob, it's probably something that's going to be reserved for more difficult fights. And if it's something reserved for more difficult fights, it's probably going to go the same route as LOTRO's combat maneuvers: most players don't know how to use them so they don't even try.
Trying to get a group to stop running off and smashing things for a few seconds to set up a regimen if all that regimen does is tack on a little extra damage or apply a status ailment to a mob that's already near dead anyways isn't a winning system. It's a, "Ya, ya whatever dude...quit being so **** about **** that doesn't matter and let's just go" system. SE needs to make sure the regimens are worth doing and as straightforward as possible or they're going to go the way of skillchains in XI...not worth the trouble.