She's sticking to the old chestnut about being able to reach people who don't normally pay attention to politics. Her party, on the other hand, are sticking to that outdated notion that MPs should be working with their constituents and representing them in parliament.
She must've realised that this is how the front bench would react, especially given the animosity between her and them. You can't blame them either, it looks pretty bad to have a serving politician swanning off to star in a creaking reality TV show (and presumably getting paid for it). Unless she somehow becomes the nation's sweetheart by chomping on insects you'd have to put your money on her getting kicked out at the next election, and unless she's a complete moron - which is quite possible - she has to have known this.
It makes me think of Louise Mensch deciding to sack off being an MP earlier in the year; it smacks of 'I can't be arsed.' And Dorries was pretty scathing about her decision to quit. I struggle to have respect for any politician who has a another job, never mind those who feel the need to go onto some shitty TV programme for spurious reasons.