re: Tipping culture and service workers entitlement

I go to an excellent Mom & Pop restaurant. Waiter brings menu and takes our drink order. Brings drinks and takes our food order. Brings food. Stops by and ask if everything is OK. Brings check. Averages 25-30 bucks. I almost always tip 25%. In this case probably 7 dollars. 7 dollars for 6 or 7 minutes work. Pretty good. Next day I go to a nicer place. Waiter does exactly the same job as the first Waiter. Bill is 50-60 dollars. 25% is roughly 12 bucks. Why should this Waiter get 5 dollars more for the same few minutes of work?