I see that Osbourne has decided not to stand so that he can 'fight for Britain' as editor of the Evening Standard. In other words he knows that if he stood he'd get a hammering in the polls that he would never live down so he's going to save himself the humiliation and make a comeback at some point in the future when the peasants have forgotten just how much of a smug tosser he was.
Can't fault that analysis... 
Except as he has one of the safest seats in the country so no way was he going to get hammered so frankly I've seen better theories.
His problem was more subtle. He was going to tough it out until 2020 when Tatton would no longer exist as a constituency and as an excommunicated non person by
Saint Theresa he'd have no 2020 constituency to stand for under the new boundaries. He could go off to his 6 alternative careers as some sort of supposed martyr and probably imagined he'd become some sort of sub cult figure with a media career .
All got torn up when she went for an election on the current boundaries

.
Have to say if he and May were both drowning and there was only one lifeline, I know which I'd throw it to and it wouldn't be that lying cow. Osborne may be inept, charmless, self centred and with dodgy social values but he has at least played with a straight bat.