People don't realize there are better ways than that. Also, if they need to enter their e-mail address somewhere they can't insert CSS or JavaScript and aren't sure if it is going to be properly obfuscated when rendered, the only way is to plain text obfuscate it.

By the way, here is a blog post from 2008: http://techblog.tilllate.com/2008/07/20/ten-methods-to-obfus...