Why you gotta say stuff like this. Shinn is human and responds in the same way most normal humans would respond. Its why hes such an awesome character.
To an extent sure. Shinn is a tragic character. His family dies right in front of him, he has no real outlet for that in the handful of years that lead to his registration into the ZAFT forces. But his entire thought process goes from being grief filled reasoning to he clearly just has a mental disorder and would probably be a monster even if his family was alive. He seeks approval from sources that he clearly shouldn't (which would be an interesting trait if he only STOPPED at some point.) He's got all the support in the world as well in the form of subordinates, friends, and veterans who genuinely try to care for him and he rejects their common sense advice at every turn, but falls for obvious manipulation at every chance.
He's just got no actual agency throughout Destiny is perhaps the biggest flaw. He's written almost like a monstrous side character and maybe would have been best as one from the start not the half way point.
His whole character is just not made to be likable, relate-able, or even sympathetic. We put people like him in mental hospitals. Then again, they put him in a 30 meter tall war machine and let him go ham for those reasons lol.
Shinn has the beginnings of a good character but because he does not evolve at all while others like Kira and especially Athurn did, Mr. Asuka is just a hard pill to swallow. Now that I think about it, Shinn is just Kira and Athrun combined, if they never took a minute to question the BS coming out of the mouths of people around them. They might have gotten there at some point if they did not lean back on Kira, but I honestly doubt it given how deep into the show we get before that shift happens and how hes still acting when Athrun bodies him in the last episode
(series might be worth sitting through just for that cathartic moment lol)