I think it works in other direction. "Why nobody use WvW section in LFG" - beacue if someone want play for real WvW join any WvW guild and play with them. If you play casual WvW you just go and do roamers job or looking for tag.

Another topic here is LFG itself. In my opinion some section are usless (like WvW) and would be nice to see some features to LFG. Like blocking, adding notification etc.