I think some kids are conservative because times are good, the economy is booming, things are stable. There's very little that truely and obviously impacts day to day life.
I agree that the environment is a mammoth issue, but it's had little tangible impact on our quality of life. I maintain that you cant be passionate about the future - you can be passionate about things that have touched you and which you've lived through. Vietman for instance, kids were having their mates drafted off to die for a stupid cause - that's clearly something to be passionate about. But no one but the best leaders have the imagination to look down the track decades beyond their desired term of office.
So in the current climate, most of the left are seen as shit kickers, and people looking very hard for problems, when they dont really exist on a level that hits the majority. Ive known my fair share of lefties whos real issues are in their childhood and feel the world owes them something - not really serious/passionate people.
This was Latham's problem in 04; a fairly left kinda guy, campaigning for pretty major changes to our way of life. But Howard merely went for the rare issues that really effect day to day stuff (interest rates, now petrol etc)
So it's irresponsible that we're happy with the status quo, but a totally understandable human reaction. So stfu; leaders shape the unknown future