This is generally really true.. most of those ogcds are just spammed mindlessly for a small % increase to dps.. no one ever uses a shield swipe with the deliberate intent to pacify an enemy. nor does anyone ever use blunt arrow or jugulate with the actual intent of silencing an enemy. same again with steel peak or jugulate (under wasp) or brutal swing.. never actually saved or used for an actual stun just spammed on cooldown... ultimately makes all those skills worthless and not needed. not to mention all the similar ones I didn't mention... you could remove all of those skills and it wouldn't have any real impact.. take both a ninjas ogcd away and they lose something like 4 potency per second.. you honestly wouldn't notice it.
moving away from ogcds you have things like lethargy shadowbind, (actually that might be ogcd) sure cast, feint, fists of earth fists of wind, dissipation, freeze, sleep, repose all of which have virtually no use ever and as such are completely unnecessary all they do is bloat hot bars (if people even bother to set them at all)
then you have skills that are so similar in whatthey do they could easily be condensed. thunder 1 2 3 for example. stones aeros, etc etc..
you can have as many skills are there is practical use for them..
the problem the game has now is so many of the skills we have serve no real purpose or function... the only function that exists is dps..
sleep is a useless skill because nothing ever needs to be slept just round it all up and aoes it down... makes the presence of sleep speels obsolete..
if content actually required more than just dps, required tactical use of heavys stuns silences sleeps pacifies etc etc etc, suddenly all those skills would be worthwhile... but as it stands they're only ever used for a small dps boost and if they don't offer a dps boost at all they're probably not ever set to hotbars.....
I wouldn't mind 50 buttons if they all did 50 different things and not 50 varieties of the same thing... and all of those different things were actually properly functional, not just used on cooldown for a loldpsincrease