I only say it's stupid because of the inevitable flame wars that erupt over what, in the end, becomes a near religious debate. To ask if one is better than the other is a stupid question. A better question to ask in that way would be what makes one better.. or what does one do that the other does not.
But even those questions become flame wars in the end. (And yes, I realize I stand at the precipice of a flame war for continuing this...)
It's also like the question just asked in this tread: http://forum.osnn.net/showthread.php?t=37999.. "Is Linux Truly More Secure than Windows?".
You'll have MS religious evangelists that will disagree.. and you'll have Linux evangelists that will agree.. and you'll have decent discussions and issues raised for a while until the thread degrades into a "my logic is better than yours" flame war sprinkled in with the occasional insightful comment and mixed in with input from the BSD supporters and the rants of the MacOS users until the thread finally dives into the depths of all things with the quips from BeOS, Amiga, OS/2 people proclaiming that the world should never have let those OS's die.
I agree to a certain extent. Simply asking the question "Is a PC better than a Mac?" or vice versa is stupid, and is not going to get you any real answers.
If you've never used another operating system before and you're wondering if it might prove to be a better alternative for you, it's best to post what you use your computer most for, and what you're looking for in a "good OS." Since no OS is perfect (contrary to what some people preach), and each one has it's strong and weak points, once people know what you're looking for, it's much easier for them to give you good advise, and honest opinions in general (unless, of course, they happen to fall into the fanboy category on either side).