Why would he step down when he had a pretty significant mandate from Labour party members to be their leader?
I think Corbyn was a bad person to lead the Labour party (I agree with his policies but he just wasn't leadership material), but IMO we should be absolutely hammering the electorate for not holding their noses up and voting the guy that wasn't Boris effing Johnson.
I agree with you that he was a bad leader. That is a failure on Labour's part as a whole, and on Corbyn's by not taking the initiative to say "You know what, it's clear this party is not going to make headway with the current leadership. Let's find a new leader that is liked by the people and get Labour in for the people."
Unfortunately the cycle continues where Tory's are fucking things up as we speak so that when Labour likely get in they will spend years putting the pieces back together. Doesn't matter who wins, the public lose.
The leaked report a couple of years ago showed the Blairite wing of the party would rather actively sabotage the party than have Corbyn in.
Corbyn was voted in by the Labour membership twice, the elected Blairite MPs didn't like that and decided to work against what their party membership wanted.
Couple that with the left-wing-hostile British media, and he never stood a chance, despite being at some points entirely capable of being elected, if not for the constant sabotage.
Corbyn could never an election though? So, I really do not see your point. The perverse argument is that Corbyn and his allies were also sabotaging the Labour party. They were nothing that was beneficial to the party or constructive in encouraging people to vote for Labour. Some of Corbyn's policies were ofc good, but he carried so much baggage that he was untenable.
The article I linked in the above comment about the leaked report gives a lot of evidence of the Blairites in the party doing what they could to lose labour votes.
I think it's reasonable to conclude that without their sabotage, Labour likely would have won that election with Corbyn as leader.
In this case liked by people means actually does his bloody job and offers a genuine opposition to the conservative party rather than just going "hey Brexit seems like a great idea" and giving team remain essentially no real major political supporters.