Many people just aren't comfortable with the Internet, and even simple email is beyond them. Just take a look at how many people keep posting back to the Ontbirds list to have themselves removed from the list. This is inspite of the fact that the info on how to do this is on _every_ single Ontbirds posting, and we get an email reminder every month.
Realistically, if you can't post about within 24hrs, the info is of limited value. So getting some people to go home, boot up the computer, get on-line, remember what their password is etc, etc just to post a sighting, is quite a chore compared to those of us who have high-speed, and only take a few seconds to post something.
Getting all the information down and making useful to other birders is also not as easy as it seems. Big thanks to Norm for always giving such good directions.