I don't know how Mr. Rogers felt about McDonalds, but I do know that he liked a little variety in his life. Mr. Rogers wrote If We Were All the Same, to allow kids to speculate ("pretend") about a lack of variance in life.
"Suppose everyone in the world looked exactly the same -- everyone ate the same food, lived in houses that were the same, and even had the same thoughts.
"How do you think it would feel to be in a world like that?...."
After a trip to the Purple Planet, etc., Mr. Rogers ends with the following words:
"Isn't it good to know that we can have some things that are the same and some things that are different no matter who we are? Nobody has to be exactly like anybody else, but people can like us exactly as we are."
If We Were All the Same. 1987. Random House, New York.