According to a message of a Mozilla member they are awashed with feedback, so it may be a way to try to force people to distill their message instead of sending huge and redundant WOTs. Remember Pascal's "I would have written a shorter letter, but I did not have the time."

If you feel the need to send something larger, there is still the mailing lists, newsgroups, IRC and of course, just posting it elsewhere and sending a link.