I don't think the results of this team are why people are angry or frustrated with Corbin. At least for me, that's how I feel. Corbin's win-loss record this year doesn't really matter that much to me.
The main things that are frustrating me are:
1) Our style of play. It's gotten better as of late, which is nice to see, but it's still not that great. Our defensive rotations and schemes are garbage, and we never seem to have that many guys cutting through the lane for open layups. We have plenty of players who are capable of doing so in Hayward, Burks, Williams and Carroll...we just aren't doing it.
2) Corbin's seemingly refusal to play the young guys. I do like how he's making them earn their play, but dammit, these guys need to be able to play if we want to see them develop.
Oh, and Al Jefferson is most definitely a top 60 player in the NBA. We may be frustrated by his defense, but we can't forget that his offensive skills are elite. To say that he's not top 60 is showing a definite bias.