Right. and what happens when they get old? how will they ever be able to retire?
It's sort of like most people turning their noses when someone (used to; now it's different) said they were starting a business: "Oh, well what happens when you fail and can't get a job? How will you ever be able to live then?" People find a way and it sounds like the people the poster was referencing, know themselves well enough to make their decisions. While on the other hand, comparing people to the "norm" many times comes from someone who doesn't know themselves and their wants well (or ignores them), and uses the norm as their gauge for "success," or what have you. For a subset of people, retirement isn't something they want or even need. One of the sentiments I hear often from those still working in older age, "What, retire? Now? I've been working my entire life, what the hell am I gonna do in retirement besides die?" or "60 years of doing shit I didn't want, so I could enjoy 15 doing only the things my body allows now."
Life's short. If you want to do things, do them. The only reason you don't is because you live in fear. There will always be drawbacks to going against the status quo, but that's the price you pay to get what you want.
Because they are currently living on not a whole lot, they are not going to need a whole lot in retirement either, because they will be accustomed to having less money.
Before you get all uppity about healthcare costs, just remember there is only one developed country on the entire planet where anyone would even think about that. They don't live in it.
As a reference point, I was reading a very detailed write-up of what a single person would spend in retirement per year, and it was more than double what I was living on working full-time as a Software Engineer.
There are millions and millions of people out there in their 20s and 30s who work part time and do whatever they want with the other time, because that provides "enough" money for the life they want to live.
I personally work roughly 50% time. I work a few years, then a quit and do whatever I want for a few years. Right now I'm driving around Africa, have not gone to work since mid-2015, it's fantastic.
My brother just built a house and had his first child with his wife. He works 4 days a week, looking to get down to 3. When his wife goes back to work she will work 3, maybe only two. They don't have a lot of money, but they have "enough" for the life they want and they spend a lot of time surfing, walking on the beach etc. They're both early 30s.