>>23560793 (OP)
He's been one of the least bad antagonists in Gundam history.
He did some shady things, in a universe where doing shady things is the normal. Trying to put our rules onto a different universe that has evolved in different ways is basically pointless.
In the end, he was a current Government supporter who put down a rebellion by one of their aristocrats who thought his fancy scheme to take over control of the Government would work... Who also brought in a mercenary group to back him up. Tekkadan was dumb for following Macgillis... But everything had been going so right for them for so long, they got cocky as hell and thought that they could change the world after the shit they already had pulled off.
Was using the outlawed Danslief like he did shady? Yes. Was he somewhat justified in using it? I would say yes. Barbatos and Gusion were basically just as bad as the threat of a mobile armor in their eyes. Nuking them from orbit was the only way to make sure to finish the job.
Yes, while Iok was under him, bad shit happened... But he also slapped that bitch down and stopped him from backing up the traitor to Teiwaz, which allowed Tekkadan an easy win.