Why doesn't Penny have s last name? All the other major characters have a last name. I've also emailed CBS THIS question. Clearly she should have a last name.

Nope. Hofstadter is not what I was looking for. They just got married, she has a maiden name and it was NEVER mentioned and that kinda bothers me because she 's the only major character thatdoesn't have a last name.

That´s the point. The Big Bang Theory´s producers said that she didn´t need a last name, she is just Penny.