“If you’re underwhelmed by Labour’s field of candidates- then fair enough. Maybe you think no candidate can win, so you might as well be happy and vote Corbyn. But that attitude is like letting sensible scepticism of whether dieting could work for you mean that you give up all exercise and sit on the couch eating giant bars of chocolate.”
Bad analogy. It’s more like gouging off your fat with a knife because you hate your body so much and you don’t care if it dies — you’ll leave a good-looking corpse.