The best comment I have got is....
"Are you sure you have to be naked to use a Mac?"
I am off course joking, most people are more interested than have any kind of negative comment to drop. Like "What makes Mac's better?" or "How come you choose Mac?" obviously I explain.
But like everything you get the occasional "Mac's Suck, Windows are Better"... I wish I had a witty comment for them but instead I rob their Windows Laptop the smile soon goes off their face...Muhhaahaha
I don't understand the problem myself, I don't try and force people to use either Machine, the fact of the matter is it all depends on the Circumstances and what you are going to be using it for.