All the towns just need to be more like Destiny. Destiny has multiple reasons for going back there (Bazaar Restocks, Crab Chance, Tower, Limited Holiday Content - Pumpkin Patch, etc). Whereas the other towns lack content.

A complete rehaul should be done in every town, give them meaning and such. Destiny has lore behind it and is filled with content. Snowtown has nothing except a hat shop, same goes for Swamptown which has no rhyme or reason (the public farming is most popular there), Yorktown has some lore but none that is recognized and the daily quest is the only thing keeping that town active.

If all the towns were revamped though, i could definitely see more people spread about the GMAP. The problem is making each town unique with its own story and content to keep people coming back. Meaning we can't have bazaar restocks or a daily quest in every town, there needs to be a variety of things to do while not becoming overdone.