I'm curious. Why do they keep letting people onto Babylon 5 who have no real reason for being there? Why do they let all those lurkers live below when they don't contribute to the overall mission of the station? Is earth so full they refuse to accept them back?
In other SF stories I've read, a colony/space station/planet might require that an arriving person have a return ticket or amount of money for one kept in escrow. Apparently the B5 universe doesn't have that policy so when whatever brought the individual out to B5 might go wrong, they have no way of getting back to Earth or their place of origin. Earth might *let* them come back, but it's not about to pay the cost of getting them there and I'm sure it's a similar situation with the other worlds.
I'm curious, though...while we saw many species in Down-Below, does anybody recall ever seeing a Minbari?