I don't think you've heard of the concept of variety. Take sorcs/sages, why would they need as many defensive cooldowns? I mean, it's not like they are supposed to jump head first into the enemy team.
The reason marauders got the defensive cooldowns they do is because it's an initially squishy class, that depends on its defensive CDs to be viable at all. And I'd say a lot of their defensive cds can be countered. How hard is it to gain distance between you and a mara? That would be ideal to shut down cloak of pain & undying rage. SWTOR pvp is all about knowing WHEN to use WHAT. People are only noticing how badly prepared they are to fight marauders now recently because of the patch that made rage management so easy, which in turn led to mass rage spec.
Basically, I am all for nerfing force smash/sweep, and upping the CD on force camo. But you in turn gotta remember, that maras doesnt have any real stuns, only stun they got is a rather counterproductive one, seeing as they stun themselves as well.
You don't need that many def cooldowns. I can keep saying this enough... You are more tanky and have greater survivability than tanks and do very high dps. And yes if Mara/sent need three cooldowns to be able to do viable dps because they are squishy... So do sorcs, ops, mercs, and all three trees of vanguard. You cannot have the best survivability and near best dps in the game and call that balanced... Ever. You do get a mez in awe, a channeled stun in stasis, a slow, and a gap closer with an immobilize for free! No talent points needed. More, abilities and improvements on the ones you already have with talents. That is unbalanced.
The counter to argument about sorcs is that they are supposed to be a ranged class and need those extra def cool down abilities to just survive melee to be able to do their damage. Tgat sounds ridiculous right? It's just as ridiculous as a Mara/sent saying it. I have one. I play it some times. Typically I pop my first cooldown continually push one button while I channel surf, after 10 seconds or so I pop the second... Push another button repeatedly, keep flipping channels... If other guy is still alive I hit guarded by the force, push my third button repeatedly and take a sip or three of water. If the guy is still alive and i havent found a channel i likeI med pak and force camo away. Then when I am hydrated and not channel surfing I go smash the war hero geared sorcs sages ops scoundrels mercs commandos in my BM gear... I avoid attacking the other classes because that would require me to pay less attention to my tv shows...