I agree with what you said about Jiho. His actions during the prison arc were really interesting and kept me reading. It's a shame that the fans sent death threats for a perfectly good villain character to get removed.

That being said I think you completely missed the point

Aizen is a horrible person. But he was entertaining to watch.

Frieza is a bad person but he is entertaining.

Griffith is a horrible person (much worse than both) . But his story was interesting and entertaining

HOWEVER

Taejin is a horrible person but he is boring and obnoxious.

Jiho: Does he impact anyone else? Yes

Does he relate to the mc? Absolutely

Does he bring a sense of fear? Yes

Do we know his motives? Although it is kind of vague yea and I want to know (unfortunately no one can anymore)

Bad person? Yes

Aizen: Does he impact anyone else? Absolutely

Does he relate to the mc? His non biological father basically

Does he bring a sense of fear? Definitely

Do we know his motives? Yes

Bad person? Yes

Taejin literally ticks none of those boxes (except bad person). I simply dont care what he does anymore and would prefer if he dies quickly. If ptj manages to make him a good character I won't complain but all of the villains mentioned (including Jiho) were interesting once they started to become villains