I'm not going to hold myself up as a paragon of saving, especially around these parts, but we managed to do this despite not finishing school until 27, not receiving any windfalls, not making much more than the median HHI of the area before 35, and starting with a decent chunk of student debt from the wife (NW was about 3x HHI at 35). DW's cumulative net income didn't exceed her student debt until she was 34, and my salary didn't exceed my inflation-adjusted starting salary until I was 34 as well due to the great recession. Neither of us have been laid off, so we do have that going for us.
I've definitely heard enough millenials express the general attitude of "woe is me, things are so much harder now, look at house prices and pensions and stagnant wages and college debt and wah wah wah, so why even really try? I want my travel, nice car, restaurants, and latte and those are small change compared to things like a house or retirement, which I'll never have." This attitude has been expressed even by co-workers, whom I know are making six figures +/-.
Sure, it's a metric that you can't measure everyone by. However, most people with a college degree and an actual career should be able to manage it.
Agreed on the multiple of salary as a metric being pretty flawed anyhow (I'm looking at you, Millionaire Next Door) - our HHI has increased substantially over the last four years. Nevertheless, while not really increasing spending, our "Whatever Accumulator of Wealth" metric hasn't been increasing much despite our savings rate going up and up. I suppose that now I'm expecting both of our salary increases to be leveling off, we'll be doing better (?).