I just hope their retirement plan isn't to live with my partner and I.
Might be worth it for you to have a small place so there is literally "no room" for your partner's family...
You might as well get some bit of happiness from something since everything else is awful. People want to feel good.
Were you poor or just broke while you were young? Poverty is far different from being in college and not making much. Poverty is much different than being short on cash. Poverty includes having limited options ahead of you and the prospect of always being poor.
What you mention may well be their line of thinking. Nothing wrong with people thinking whatever they want. I simply did not want the kind of future that such a lifestyle would bring me (i.e., remaining poor).
Saving money, and leaving cheaply when poor will help you develop a habit for when you are financially in a better place.
However saving 20% of your salary when you make, say $2,000 per month in NYC/SF/LA, is not going to be possible. Not only that, but it would take 4 - 5 years to get to $20,000.
My thinking is there is a minimum people need to make before they can save meaningfully. Below that point, saving is just an exercise to get ready for a better financial position/earning.