I know it seems weird but think about it. Harold is the only one nice to Heather, Harold's now single, and They did team up in TDDDDDDI. I'm thinking maybe in a few more episodes, they'll become a couple.
Also, I think Justin is the new Heather. He's manipulated a few people (like Beth and Lindsay), and he's been mean all season. Heather's not really been that mean this season. Sure, she throws in a few mean comments, but that's just Heather. She hasn't tried to manipulate anyone and she has had a couple good ideas (Like in the epi where Izzy was eliminated) but no one listened to her. I think more people are being mean to Heather, than Heather being mean to them.