I'll just address the underlying sentiment that credit card debt is just fine and totally normal.
It's really a question of poverty vs convenience. If I use my credit card because it is convenient and I can pay off my bills, great. No problem. But if I am so poor that I have no choice but to put everything on a credit card, then every purchase is 10%, 20%, or even 30% more expensive - heck, it might be 3000% more expensive because there are many people who are making minimal payments just to get by every month.
So, no, you silly analogy about your grandparents is not what we are talking about here. We are talking about people right now, today, who are living paycheck to paycheck, not sure how they are going to pay for food and for the medical care they need, and making really hard choices. And your mockery is inappropriate.
I think your point that a credit card can't save someone that consistently spends more than they earn is correct.
Neither will a few thousand dollars in cash.
I don't believe 60% of Americans are in this category anyway. I don't think anyone seriously does believe it. Do you?
What we are talking about, in my view, is whether having substantial cash reserves has any relationship to risk of imminent financial disaster. Or if it's a weird anachronism.
This seems like a caricature of the opinion of someone who grew up in the Great Depression and never accepted credit cards as legitimate tools.
Saving money from your first good job until you had several months worth of salary was traditional advice, like, in the 1950s.
In the Depression, my grandparents raised rabbits on the farm for food! Should we be concerned that the average person doesn't have any rabbits in reserve and is therefore on the brink of starving to death?