*Sigh
Know what the problem was? (Is still)
Separate boards for passenger missions, while only one board for every other type of mission. All of them.
Made it fairly simple to flip the boards to fill ships with the bulk passenger missions you wanted.
Can't do that with Data missions, or cargo missions (both of which PROBABLY have the distance modifier still active)
Passenger missions have a single source that will provide 8-12 missions of what, 3 different kinds of missions? (Bulk passenger, VIP transport and sightseeing/exploration)
The regular mission board will provide 8-12 missions of 8 different kinds of missions (that I can think of off the top of my head: cargo transport, data transport, massacre, skimmer, assassination, mining, source and return, naval) and there are probably a couple I'm missing.
It made getting the specific passenger missions you wanted MUCH easier than flipping the insanely uncooperative mission board to try and fill a cargo ship or stack a bunch of data missions.
So that's what people did to make credits fast.
And it's simply human nature to take the path of least resistance.
The solution is likely two-fold.
First, FDev needs to figure out what the MAX profit per trip they want someone to make, and scale the distance multiplier so that a fully loaded Passenger ship will hit that, maybe a little over to account for not maximizing passenger capacity every time.
Second, the main mission board needs to be made either a) intelligent, in that you get offered mission based on your current ship's configuration, or b) filterable, in that the missions are broken into classes (combat, transport, supply possibly) so you can select the type of mission you are looking for. Then establish they payouts so the income per hour pretty much matches up with the number established for the passenger transport missions.
*dons fireproof suit