The Mac, in my opinion, has never been anything but a watered-down version of the PC designed for ease of use. There is really nothing you NEED a Mac for that a PC cannot do. Especially now that Macs use Intel processors.
The Mac has more proprietary hardware, the parts cost more, and it has never been as successful or popular as the Windows PC. Also, on a PC, you've always been able to choose to install an alternative OS like Linux, if you wish. On the Mac, the PPC processor prevented this until recently, unless you had very specialized software. Also, the Mac OS just isn't set up by default to give you as many options as you have on a PC. It may be a little simpler for people who don't want to learn about their computers, but people who actually use their computers for anything meaningful seem to prefer PCs. The only things I've heard of people needing the Mac for are video editing and graphic design, and that's only because there's a proprietary program made by Apple themselves exclusively for the Mac.
The PC also has better support for legacy systems, better business/office applications, and is in general better known and supported by experience. Most environments have deployed PCs, for better or worse, so going with Mac really places you into a smaller, more expensive niche group. I also don't like the way that Apple tries to make their OWN application to cover all the bases, and thus discourages people from using third-party applications on their computer. It's allowed, but still... it's discouraged to some extent by the design of the OS.
Another issue is that I dislike Apple's anti-competitive business practices in general, and feel that iPad/iPhone is a sub-par platform. And on THAT platform, you actually have to hack the system to install third-party applications that haven't been approved by Apple. You can't move your iTunes music to another phone easily, and they try to lock you in. I really don't like Apple's dominance of that industry, so I also think it's a bad idea to support them here.