Because most people don't know what FTP is, if they even know it exists - much less how to use it? Ditto on HTML. It might be a bit flaky, but for the average

Because most people don't know what FTP is, if they even know it exists - much less how to use it? Ditto on HTML. It might be a bit flaky, but for the average end user its significantly (perhaps "infinitely") more useful than an FTP client and a text editor. Maybe what you want is Google Sites?