My guess is that people (like me) who use portable RSS readers have a lower than average commenting activity level.
I don’t have any data to support this hypothesis - it is based on a best guess and a lot of user centered process design. Basically, systems are more likely to be used when they are easily usable. I know that this sounds like an empty truism, but compare the user experience here:
- desktop RSS reader: goes to the comment-worthy post, leaves comment.
- portable RSS reader: goes to the comment-worthy post, enters Name/Email/Website details, leaves comment.
The difference is that the desktop reader usually has their Name/Email/Website details remembered by the web client. This may not seem like a big deal, but when you’re dealing with a device with a limited QWERTY or 13-key phone text entry mechanism, every character saved is a blessing.
It is hard to imagine a world where name and email are not required for comments - until portable RSS clients have matured a bit more it is probably just something that everyone will have to live with.