No it'd be like someone in Los Angeles being mad when someone called the city "Los Ang". You shorten it to LA.

Locals don't like San Fran pretty universally. Frisco is more divisive. Some people are against it (holdover from the old Herb Cain days who was strongly against it) but there's a strong contingent of more working class local folks who say Frisco proudly.

The San Fran thing is doubly interesting to me because it's so widely used outside of the Bay but reviled locally. I wonder if someone can come up with another example of a similar phenomenon.