You don't seem to see Corbyn as the problem. I can see Labour in opposition for every day that Corbyn is leader.
I would imagine that if Labour get a real kicking in 2020, they will replace him then, which is too late of course.
Loyalty is admirable, but a party is bigger than one man, and in the situation that the man is the problem, you have two choices. Replace him, re-energise and reunite the party, and win the next election, or keep him and lose.
I'm not a Labour supporter, but do listen to what people are saying, and my admittedly small sample is hearing a rejection of Corbyn.
One thing that the right seem to be capable of doing, which the left seem to be incapable of, is at least presenting the image of a united front, come election time. Fighting like cats in a sack doesn't endear any party to the general public.
As I said, I'm not a Labour supporter, but I do not want to see the current government in power until 2025, and perhaps beyond.