Hmmmm. Bullshit alert going off.
Every generation needs to come of age, get their education, look around in the world, and fit in. Many times this involves a lot of protesting and asking for change, complaining about the way things currently are, and experimenting with various alternative lifestyles. This is good for everybody.
What some observers see -- probably because of the way the press reports it -- is a lot of kids who are ass-deep in debt, lack the education (even though they've graduated from a nice college) to be employable, and instead of adapting to the world as they see it, are stuck in a mode of complaining and waiting around until something comes their way. This is by no means all of them, but kids like that make for a good newspaper story: "Still living in his parent's basement at 35, Joe Smith emails out 100 resumes per day before going to the Starbucks and playing MMORPGs all day. 'I'm just not sure where the management jobs are,' the Art History major says...."
To a story like that, sure, people will say something like "perhaps instead of insisting the world conform to your ideas, you should learn to like the world as it is and adapt. Many have found that this leads to a happier life." or the shorter form, "grow the hell up, kid!"
People who offer this advice are not trying to be callous, cruel, or insensitive to the plight of the young. Nobody is saying to give up on your dreams. It's just that big goals like being an astronaut often begin with flipping burgers down at the Mickey D's, even for people with 4-year degrees.
Like I said, I blame the press for setting up this "fight". If you ask me, most college grads already have this figured out.