Many people have asked this question, and the most significant answer is simply because a Macintosh will not give you anywhere as much grief as a DOS box. Everything about a Macintosh is easier to use than Windows, even Windows 95. After all, as much as Microsoft tries to hide it with Windows 95, they're still DOS boxes. The proof is in the pudding though. Here's my 2 year old daughter Jordan booting her Macintosh.
Nothing is as fickle as a two year old.
In fact, she's already better than a lot of adults I know, although she hasn't had to save any files yet. That's always the first stumbling point for any Macintosh user. Then it's that RAM versus hard disk issue. But I digress. The thing I can't really prove is that she could add a new hard drive to her computer.