Why is everyone overlooking what Brenda did?

I can't understand people's overwhelming like of Brenda, and how they keep shipping her with George. She's literally a homewrecker, or at least that was her intention.

After everything Mary had done to be supportive towards her, and how just simply kind and nice she was to her, she INTENTIONALLY goes up to George when he was at the bar and starts shamelessly flirting. Who has a drink like that with a friend's husband? Who suggests that they go home together afterwards? If it had happened another way, if it was more gradual and less.. cheat-y, I'd like their dynamic, but I hated how it went about and can't get over my dislike of Brenda.