I give Mac credit where due. Certain devices have their niche. The graphic/sound side of the house mac is solid.
I play games. I use a PC so I can play games made by people besides Blizzard. I build my own PC. My desktop+32in 1080p hdtv to use as display cost less than a weaker mac.
Mac shoots for a different section of computer users, and their market share reflects the size of that group.
Beyond that, frankly, there's no point in even trying to discuss the merits, its worse flamebait than religion.