Earlier quoted context omitted.
Why "hate"? I personally find fascinating that kind of implicit cultural rules.
Because once you see the pattern it can become an oppressive social requirement. I'm american but have been living in Czechia for about 15 years, and I've seen friendships blown up due to shit like "we visited and he didn't even offer us lunch", or "she didn't even offer to pay for lunch". It's fun when you are a visitor and you can view it from a distance, but when it's the local unaware social OS, it's got a far di…
As a Czech (and a very picky eater who refuses a lot of food offered) I can't really confirm most of what you wrote. Paying for other people's lunch is not really a thing, other than perhaps in the context of a date (where the man is expected to pay).
Food is important mainly in the very old, wartime generation and even there it's mostly in the context of a family.
> Refusing food on a visit is basically equivalent to taking out a gun and shooting the family dog. You're likely to never be invited over again, and people will think you are a complete asshole.
It kind of looks like you've been having a bad time in Czechia, but this is very far from representative.
> There's absolutely no "I was in the neighborhood and thought I'd pop in and see what you're up to".
This part is true, but it's IMHO a "global-north-wide" change in the past few decades. It used to be quite normal 30 years ago.