It's not really about safety nets since most people don't discount (or account) for them (they're in the future). It's about disposable income, and for huge numbers of Americans, that's in short supply due to the exorbitant cost of housing, college education and health insurance & care.
Safety nets in my mind are what kick in after a person has no way to pay for necessary stuff by themselves.
Disposable income is what gets cut down by the costs of necessary stuff.
Very few people are going to not go to dinner because they are aware that if they become indigent US society will not pay, and thus feel an obligation to save.
Lots of people will not go to dinner because they've already had to pay for (... you name it ...)
Way too many (many millions) have no insurance or inadequate insurance, but that's a problem we need to fix, not a description of the country as a whole.
The problem for most Americans is that what is not covered by insurance is still too expensive for them, but that's a subtly different problem than "no socialized healthcare => everyone has to pay out of pocket for any healthcare they receive"