Bear in mind, this is the generation that now has to deal with a university degree mostly being *required* for the most rudimentary of jobs. From photocopying technician to Starbucks employee, degree inflation has now served to make it impossible for you to even get your resume read for most generalist jobs if it doesn't have a uni degree on it. These kids were told that a uni degree was the absolute necessity for a comfortable middle-class life and career - then, when they came out of their uni programs, degree in hand, they were bluntly told that a BA/BSc was often just the bare minimum for a minimum wage job these days. Or, even worse, that they should have considered trades - the same trades that they were dissuaded from pursuing while in school because 'a uni degree is what you need.'
Hell, forget 'these kids', *I* was told that - I'm part of this generation, albeit slightly older and from a somewhat different cultural and ethnic background. So what alternative do they have to staying in school until their early/mid-twenties? Same goes with living with their parents - it's not like they *want* to live with their parents and put off the milestones that they were told were an everyday part of life (moving out, getting married, having kids, buying a house), they can't afford anything different because of the financial situation they're left in post-graduation, often working minimum wage jobs with a degree they were told would guarantee them a more stable life than what they're now living. And they have to get a degree, because - well, see the first paragraph. The new school diploma, more or less.
You're right, it's not their fault. It is the fault of a society that told them that uni was the be all and end all of societal advancement, that studying hard would bring rewards, that a uni degree would secure them a future, and that it was *worth it* that they spend their early/mid-twenties earning that degree. And, personally, having gone through a bachelor's and a master's at a 'prestigious' university in Canada, and seeing the reality of the job market as it is - biology degree holders working tables, engineering and mathematics graduates sometimes spending years unemployed or underemployed, politics and economics and sociology graduates interning and endlessly scanning files for *free* (gotta get that experience)...
Given all that, a bit of bitterness towards society is not unreasonable for them to have, I think. Especially when society as it's structured in the West is generally weighted towards the elderly over the young, and when the young are being bluntly told not to expect any of the benefits their parents and elders took for granted. These kids graduated from university as the most highly educated, most generally knowledgeable, most technically and socially adept generation in history up to that point (just by dint of how many of them went to university and grew up learning those skills), and then got told that they were lazy, not good enough, deluded, soft, and 'sensitive'. And when they ask for taxpayer help to earn what is basically a glorified school diploma at this point, they get told they're 'precious little brats' by the very same people who will be the last to experience benefits and societal protections that the Western world has decided young people won't get.