Her reasoning was:
We need to shut down an Alliance port.
But we can't beat the Alliance in a straight-up fight.
! We will do a sneak attack against Teldrassil !
? But won't the Alliance retaliate and beat our asses ?
! We will hold the civilians hostage !
? But won't they resist our occupation ?
! We will break their spirit by killing Malfurion !
? When has a faction in Warcraft ever been demoralized by killing their leader ?
! ... !
Okay, so that was dumb, because of points 7 and 8. But fine.
Now, the plan has changed.
? So we can't break their spirit. ?
! Let's burn their tree down. And all the hostages !
? But won't the Alliance retaliate, and beat our asses ?
! I SAID BURN IT !