Yes, motives can change. I am not fucking arguing otherwise ... I am arguing about how they changed. She knows Sylvanas was planning to divide the Alliance ... so she goes and divides the alliance. Tyrande isn't supposed to be a total idiot, but whatever, the prior expansion she let an evil entity manipulate her into chasing illusions. So maybe she is secretly an idiot.
You need to stop complaining about shitty writing if you think Tyrande was the most consistent character. Anduin, Sylvanas, Genn, Nathonas, Lor'themar, Jaina, Talanji, Baine, Saurfang, etc ... all more consistent. And yet you think Tyrande was consistent?
And let's just go here, you think Blizzard is "shitting on Night Elves" but gave Night elves the most consistent character? Yeah, that's not shitting on.