I was never a fan of his during the Shield days, I definitely thought he was the worst amongst the trio but I wouldn't say I hated him. Nowadays though, I personally hate him. He's pretty bad on the mic and on a good day he's only average.
At the end of the day though, it's really the booking and the fact that he's shoved down our throats constantly. There are so many other wrestlers that constantly have to take a backseat while the same guy is pushed to the moon. He main evented 3 Wrestlemanias in a row and he's going to main event a fourth in a row. Has anyone else even had that honor? Just slow down with him, attendance is going down at shows because they make the rest of the roster feel completely insignificant and they won't try to make new stars, they just push one guy that the crowd isn't into. Meanwhile, they make him out to be invincible after he's been kayfabe murdered several times and still kicks out at two.
FWIW, I also hated Cena until recently when it was the same schtick with him. Anyone who is constantly shoved down our throats, takes a beating, and miraculously wins every match is just so damn boring and predictable. If you're going to make someone invincible, do it like they did with Asuka in NXT. We didn't see her several times every week and she was the one putting in most of the offense rather than getting her ass kicked and always kicking out at 2 after 4 finishers and then taking down her opponent in one finisher... The matches with Reigns just aren't believable with how they treat his finishers and others.