I've proven that my Microsoft optical mouse isn't nearly as accurate on other surfaces and, besides, the materials that the "feet" of the mouse are made of are formulated with the assumption that you will be like most normal people and use a mouse pad.. It's formulated to glide smoothly on neoprene or nylon or plastic, not laminate or shellac...
Seems to me simply a desire to be a rebel by not using a mouse pad, as it hurts nothing, and you can even get ones like I have with a gel wrist-rest to help prevent carpal tunnel... What's the logic behind not using one when they're given away as promos by just about every company, and you can purchase a top of the line mouse pad/wrist rest for under $10?