Because Varian already got his “lesson” from his initial attack on Ogrimmar. He underestimated Garrosh. The same could not be said of Tyrande, if anything she probably thought the orcs, particular Garrosh was nothing more than a brute without a brain in his entire body.
Tyrande has never been that patient either, the events in Darkshore emphases one of her greatest weaknesses since Warcraft 3. She can be rash and impulsive without giving her actions a second thought!
Yes! Did you not player the Frozen Throne? She literally jumped infront of a group of Scourge and ended up causing the bridge she was on to collapse!
A noble gesture but still suicidal. When Maeiv of all people is trying to be a voice of reason(and Tyrande, snarky as ever talks down on her even when she ended up being right!) and telling your plan is going to get you killed, well lets just say maybe you need to reevaluate just how much risk you do take.
If anything this just highlight how far Tyrande is willing to go when she thinks what she is doing is right!
That’s largely due to the Hayes Code still influencing popular media and refusing to show suicide in anything but a negative light the looking the other way when a fool gets themselves killed. There are a few famous heroes who if they survived their own last stand would have been held in contempt and disgraced by the same people who put them on a pedestal.