There's a big difference between sticking by your principles and leading a party.
Britain is a parliamentary democracy and Corbyn has one of, if not the worst, voting record of his party. He has even voted against party policy since he became leader. How can someone like this ever expect to command the loyalty of other MPs and thus form a government?
If you really want him to lead the party then you should be careful what you wish for.
If, as seems likely, he is re-elected as party leader then it will be champagne over at Conservative Central Office. An early election via a constructive vote of no confidence followed by a Tory landslide is likely to the result. Not only would this give the Tories the majority they currently don't have to repeal the European Communities Act, but it will also let them really get on with dismantling the health service and what's left of the welfare state. Oh, and any thing like the BBC that refuses to toe the government line. I bet Murdoch et al. can't wait for Corbyn to be re-elected.
Until the UK's electoral system is reformed there needs to be a binary choice for the non-partisan electorate. Corbyn and his Militant throwbacks are simply not viable for any of us who remember the lost decade of the 1980s. Much as we might have admired Michael Foot's ideas (he was so much more than Jezza could ever aspire to be) his complete failure to deal with the Militant Tendency is what gave Maggie three landslide elections.