Please look at Mage Squirrel.

[Aguni]

snip

I am inclined to disagree with you actually.
Yes, the war tree does lessen the effect of your stun.
At the same time, that opportunity allows you to get lose.

CC should never be used to have your opponent be completely locked down while you wail on them.
It should be used to place them in a disadvantageous position or situation.

For example, the warlord pull is among my favorite abilities.
Sure, it does not immobilize them, but it yanks them towards your front line so that they can be focused down by your team.

It is why warrior CC is fine in its current placement. Primarily because while you cannot lock down your opponent, you are placing them in a situation that is disadvantageous for them.
Being able to remain in melee range? That prevents a mage from using hard class abilities.
The root? It forces them to pop a break free or a flicker to try and avoid the rest of your team from coming to aid you.

As it stands currently though, I think mage CC is in a worst scenario.
Squirrel doesn't possess any tactical significance.
It breaks on damage so using it to keep someone out of a fight or keep in a bad place doesn't work. So they can eat ANY hit and immediately return to what they were doing.

So the only thing mages use it for a cast time reduction.
It is used offensively, not for tactical purposes that may benefit the team.
Part of this is due to how warriors and rogues work.
They get close so quickly that the cast time reduction is immediately necessary because any instants they possess, are far too weak to get the job done before they die.

The most useful CC tends to come in the form of snares, but Riftwalk and Rogue ports break those constantly, destroying any tactical usage one can gain.

So while a warrior may not get to lock down their opponent, they are still being used to hinder their opponent.
Mages? We use our CC like a damage buff, that's pretty bad.