I enjoy crafting and doing it wholly, ie, not using the MB, so for me it was more a case of necessity as its really not possible to do all facets on a single char.(I know technically you could, via getting the mats each time just before construction, but that's just.....)
Trading across chars is done via a small section in the guild bank set aside for this very purpose.
If the crafting mats were handled like Guild Wars 2, Elder Scrolls and some other games, then I would probably only have a single char.