The comments are particularly interesting and insightful. I liked the way the article was written - it made its point well.
Basically, if simple folder encryption is all you need, the built-in encryption service in Windows XP (or free software like TrueCrypt) or Mac OS X's encrypted disk image feature are, if configured correctly, incredibly simple to use.
If you want a more broad data protection method, which approach to take depends on your needs. Neither BitLocker nor FileVault are perfect solutions, but BitLocker's awfully nice if your computer has a TPM, and FileVault focuses on your home directory, where your sensitive data ought to be anyway (plus, if your computer has multiple users, FileVault can be applied per-user, unlike BitLocker).