I think Kyrie is pretty polarizing on this board for a few reasons.
1) people really invested themselves in arguing the trade, and at some level, want to be right despite the fact that IT has basically not played basketball. Crowded pouted his way out of Cleveland and is an average backup, zizic is irrelevant and the cavs got a project point guard in sexton (he could be good eventually but he isn't exactly doncic)
2) people are Lebron fans, and in some Lebron fans minds, saying Irving wanted his way out of Cleveland for valid reasons is viewed as an indictment on Lebron.
3) he is a weird guy that takes controversial stances, many tied to his Native American heritage. If these views are different or weird it is harder to root against the guy.
4) he is a bad defensive player, though better than he was in Cleveland. For fans of a team that built their squad around the scrappy defense of guards and wings like smart, Bradley, crowder etc, this can be upsetting.
5) we are not playing well as a team and everyone is upset with everyone. But stars and guys getting money, justifiably, get the most