Rather than 'power' (which is rather nebulous) I think it's more about 'making a difference' that means they suffer the brickbats. You don't get to change the way things happen by being in opposition whether you're popular or not and however passionately you believe it is right. And being in a position to make decisions means - almost by definition - you can't please everyone. I have no idea who 'Mr Ginger' is supposed to be.
Being in opposition is an awful lot easier than being in govt. I think this is a pretty mature answer from Danny A, esp given the insurrection going on inside his Parliamentary party over tuition fees.
And I'd agree with you if it weren't for the fact that the current crop of politicians appear to be doing everything but currying favour and keeping power. If someone was genuinely only concerned with the perks and the cushy jobs then they would 'do a Berlusconi' i.e. throw a good party whilst watching their country and economy burn around them... rather than chance being voted out for doing something bold but unpopular.
Cynicism has its place, but the facts are far more interesting.