GET and POST already have widely observed distinctions in how they should be handled. For example, try hitting refresh on a page that was arrived at via a POST request. That behaviour is pretty much common to all browsers.
His point was that at minimum you still need a GET and POST for read and write. So comparing the numbers against bike-shed implementations is moot. Of course the number of reads will be significantly higher.
Problem is, in a lot of circumstances, you still have to rely on GET and POST with a header like X-REQUEST-METHOD set to tell the server what you really meant.
Usually, this is not the server not supporting it, its a workaround that the server provides so that you can consume the API without AJAX from HTML forms, which are restricted to GET and POST.
EDIT: Although in some cases there is an issue that people choose not to configure it on the web server, and instead use headers or other mechanisms to tunnel the "real" method to the application. But most servers do support it, this seems to be a mechanism for routing around administrative issues in organizations.
http://en.wikipedia.org/wiki/Representational_state_transfer...