Because Illidan and Altruis were both portrayed badly and are being given a "reboot", or something, regardless of illogical it makes the previous events look.
I'm a good person. Please, don't insul't me. I don't want to have anything to do with a socialists even in a nationalist form. I don't care whether someone is loyal to socialist swine like hitler or communist donkeys like EU leaders, all that matters to me is their loyalty.
Frankly I would have preferred a 3rd option. Banish them both for arguing when there is a bigger threat at hand and make Kor'vas the 2nd in command. Those to are obviously not prepared(lame pun intended).
Right. Can I make a suggestion? Don't say things you know nothing about ok?
Freed the Orcs? He was forcing Maghar orcs in Hellfire to become fel orcs.
Broken were dead anyway? Perhaps, but Illidan betrayed them, forcing them to be drudges and slaves under him when he promised them salvation, they traded one slavemaster for another.
"A bit bad" Is hilarious.
Yeah, he "Freed" those demons right into his control, using his power source to keep them like addicts who need him.
If Mardun was crucial, why didn't Illidan roll up to Shattrath and go "Here guys, I have this plan, let's call a truce and hit the Legion where it hurts"
It was a covert operation because Illidan is an insane egomaniac.
So.
His eyes : ok, yeah. Great personal sacrifice... Give that Illidan guy a cookie !
His soul : he never sacrified his soul, he let it be corrupted by his greed for power
His love : as you said, impossible love, rejected by the woman. Doesn't seem to be such a great sacrifice to me.
His brother : he ruined that quite alone, by betraying his brother and his race for selfish purpose.
His sanity : so we agree Illidan is insane (for power). That's not the kind of guy I would blindly trust (hello Kayn).
Loyalty isn't eternal. If that which you swear loyalty to proves to be false, or fundamentally changes, you certainly don't owe it your continued loyalty.
That, above all, is why I went with Altruis. The Illidari are willing to sacrifice everything to stop the legion and save Azeroth... but it's frighteningly easy to imagine a scenario where they stop caring about saving anything, and care only about power... to envision a world where the Illidari triumph over the Legion only to become worse than the Legion ever was.
If that happens, we want people that would stand against it. That would be loyal to that which they swore loyalty to, rather than the leader and the flawed course their leader has chosen instead. Altruis will do that. Kayn won't.
(Of course, the irony here is that every Blood Elf in the Illidari has already done that once, by choosing to forsake their rightful Prince when he joined forces with the Legion.... so if loyalty cannot be transferred or abandoned under such circumstances, you are effectively arguing that all blood elves, including those of the Illidari, should have sided with the Legion when Kael'thas chose to do so.)