Corbyn has done one thing in that he has put leftist policies and focus on the agenda. The problem is its the Labour party where that has happened whilst the rest of the country is residing pretty much on the centre and right of centre.
Questions need to be asked about all the MP's however. Even the Blair wing is a bit of a joke at the moment. You have MP's like Kendall, Cooper, Creasey, Jess Phillips etc. joining Harriet Harman in focussing plenty of time on offensiveness, womens/equality issues and refugee causes. All of those are noble causes but I can see why many people feel a sense of detachment from MP's like those.
The whole Labour party need to have a think of what they are actually there to do.