If you have wondered why there are not enough tanks queuing for HM's and raiding, you only have to look at the mechanics in this game.
Nope, it's because people playing knight want OP sentinel, people playing vanguard want OP assault and people playing shadow want easier leveling with infiltration stealth boost.
Just about half of everything in this game stuns the tank, or knocks me back 100 feet and snares me, or CC's me, or stuns me, knocks me back and CC"s me.
That's odd I've fought everything in this game and not even 1% does that more often than the cd on my gap closer if you cannot INTERRUPT it.
The issue is exacerbated because DPS tend to just jump in .01 second after me and start blasting on the thing. Meanwhile I'm two miles away because I've been knocked back into the last room and am snared and/or rooted and some idiot Marauder is getting laid on by some huge robot and complaining that I can't hold threat.
Taunts: put you on top of the threat table giving you 1.3x the threat of the previous threat holder and making said mob attack you for a few seconds even if during that debuff someone else would have pulled threat.
You have 2 taunts. Can't hold threat? Use your high threat moves -> taunt -> aoe taunt right after your taunt runs out putting you pretty damn high on the theat table making it nearly impossible for DPS to get threat again.
You have all the tools you need to be perfectly fine tanking and dealing with the enemies. Learn how they work and know when to use them.