I've always felt that people need to use the tools that get the job done for them. For some users Linux works very well, while for others it might be a Mac or something else. So if a Mac works for this guy, then more power to him. However, there are some downsides to Macs. You might end up paying considerably more for lower powered hardware, and you lose a lot of flexibility and control over your computer. Some people don't mind this, but for a lot of Linux users it could definitely be a deal breaker. When you enter Apple's world, you do things their way and that could end up being more than a lot of Linux users can tolerate over time.