If people want to leave early for their own personal reasons, then let them leave. They've paid for the ticket, what business is it of anyone else's?
I sometimes leave early, to miss the traffic, as I have over an hours journey home. But it depends on how the match is going, a bomb scare wouldn't have made me leave early today, but I won't condemn those who did, perhaps they've learnt a valuable lesson in judgement?
But while we're on the subject, how come those who head to the concourse ten minutes before half time and come back five minutes after, get a free ride when ever this subject comes up? What's more, there's a lot of United 'fans' who don't even fucking turn up in the first place........just saying