Ya know, it's interesting... Illidan was ostracized for taking unto himself external power to pursue his own agenda which transformed himself. But now we have Tyrande taking unto herself external power to pursue her own agenda and it transformed herself.
I think the main difference is that Tyrande is a ticking time bomb and people (her friends and family even Horde) are worried about her. If Illidan died from such a thing nobody would probably care.