Some of us have been feeling that Greyport has been turning into an after thought.
I can walk to devils district and Sharps with zero effort, but have to take a boat or ..intresting route to reach Greyport, Greyport also isn't a pass through district for young adventurers. (Unless you know and are lazylike me)
All this makes the district more isolated, and that hurts its shop keepers.
Just give them a shiny portal.
It won't solve it all, but it will make Greyport somewhat more welcoming.
P.s. Devils district could use a banker. (Or is he just hidden really well?)