It's not "charmingly naive" to believe that users know the difference between a can that says "Coke" and one that says "Pepsi".
And if that was the comparison we were actually discussing it might be relevant.
There is a difference between being stupid and choosing not to invest time and energy in something.
Indeed, and a great many computer users (which means many millions of Microsoft customers) choose not to invest time and energy into understanding how a computer works. Microsoft has no problem with this, but it does mean they need to ensure that when those users buy a "PC with Windows" they don't get "a PC that could run Windows, but right now it's booted into BeOS". Because Microsoft (not Be Inc, not the guy on Slashdot promoting BeOS) ends up with a lot of the support costs if that happens.
If it's "elitist" to believe that some people don't care about computers then I guess I'm an "elitist" by your definition, but I caution you that this is an unusual definition which is likely to cause you problems.