Maybe. But where was he, and where were the rest of his party when this abomination was being shoved through parliament? Abstaining in the commons and cheerleading it in the lords. So pardon me if I don't buy him being a decent chap having any bearing whatsoever on this issue.

You don't know he's a decent human being. He seems nice but has never been tested. Lots of tyrants throughout history have come across as nice in casual interactions and then shocked people with their behaviour once they got power.

Corbyn catches flak because despite loudly proclaiming how straight talking and honest and pure he is, he refuses to disavow Marx (rather: dodged a question asking him to in a classic politician style), and praised Fidel Castro, both men whose ideas and policies caused profound suffering on a massive scale. That rather implies that if Corbyn ever got anywhere near actual power he'd rapidly start abusing it.