No, and all the pics of plastic guns on this thread just prove it. If I had just one gun for self defense then I would not care what it looked like as long as it worked.
I'm fortunate enough to be able to buy guns for more than just utilitarian purposes and when I do I like to buy guns which are both functional and beautiful.
To some extent I agree that beauty is in the eye of the beholder but I can't imagine anybody who thinks that Rosanne Barr is more beautiful than Sophia Loren. Same goes with plastic vs. metal guns.