Because when Hisek casts Aim and you bubble/BoP, it kills you anyway.
Meanwhile all other classes can cheat death, vanish, spectral guide or shadowmeld.
I understand that this example was a long time ago, but I still remember being very salty about it.
Since then I've noticed many examples of paladin utility being purposefully disabled in raids while all other classes could still use theirs. I honestly have no idea why that is the case. For example on Kromog, tanks get a stacking slowing debuff. On my monk, I would use transcendence or just roll, on my warrior I'd heroic leap away and charge back etc. Tried to use freedom on my paladin - nothing.
During PTR on Velhari, I said over teamspeak that freedom stops damage from the movement preventing aura. Made me a bit said that some people actually believed it for a second. They didn't know the paladin curse.
Just last night I tried freedom when I got slowed on Etraeus and it had no effect again.
Oh, had one player who usually soaks missing on Helya last week, so I was nominated to do it since DI is just like cheat death. Stood in tentacle, DI procced, DS went on cooldown and I died.
If the paladin spells actually did what the tooltips suggest, their utility would be strong, sadly it is not the case.
On a positive note, I think that paladin are in a better spot dps wise than they were since I started playing it in Cataclysm and in the end that's what matters the most in most situations.