Yes, it is just a browser and not worthy of argument, but it is a matter of personal taste and 'comfort'.
It's like clothes -- they're just material to keep the weather off you, but we all make preference choices (even Einstein had to choose the style of suit that he had multiples of) based on comfort and aesthetics. Some people even get quite worked up about
Maybe we could do a make-over TV show but with software instead of clothes?
Interesting I have a mental picture for users of the following:
Safari - Fasion Concious, Slightly pretentious and loud, likes to be seen at parties, maybe owns a sports car.
Firefox - Young and thrusting types who like to rebel a little (not too much though)
Chrome - Wouldn't be seen dead running Safari.
Opera - Well, its not your Dads browser, but ..?
IE - Sad old geeks who are more concerned with other things( as long as it gets the job done).