I have been thinking on how to celebrate my birthday, I thought of inviting my parents to my favorite restaurant. When I brought it up, they were all upset “why don’t you invite us to your home? Why don’t you cook for us? Restaurant is all reheated food, home cooked fresh food is much better” etc. We have lived in Europe for almost my whole life, I don’t really understand what’s wrong with going out to eat or why they expect me to invite them to my house and prepare a festive meal on my birthday.
I get the appeal of a home cooked meal, but that doesn’t automatically mean that going to a restaurant is a bad option. Also I don’t get the entitlement, where do their expectations come from?
Sure, but that’s an opinion, not a question. Clearly they consider it a bad (or at least less desirable) option.
If as you said this is a Russian thing and not a your parents thing, then presumably default social expectations. That’s what they’re used to, so that’s what they expect you to do, in the same way people in Western countries expect Christmas gifts. There’s no deeper answer unless you want the historical background or an explanation of why social expectations exist.