I' not sure what the point of crew is at the moment. Crew management feels like busywork with no challenge of any kind involved, it could just as well be abstracted into a ship stat. I think crew should be either tied into an interesting gameplay mechanic or crew management should be expanded into its own sub-game (with pay, health care, loyalty etc., basically the direction Achataeon is suggesting).
I'd prefer the first option, though.
One way to do that would be to transform acquiring crew into a real challenge. If you can't just buy them in shiploads at every station but have to actively work, search and fight for people, it makes them so much more valuable. Maybe you can only hire (any more than a trickle of) crew after you personally helped out their home market during a food crisis, or assisted their fleet that was under attack, or fulfilled a mission. Basically, get popular with them.
Maybe that crew value increase would make it necessary to have very sub par crew (basically street scum, refugees and idiots, with extremely slow level growth and a big ship performance deduction) still widely available so you don't get stranded too easily, though.
One other thing that might be interesting is if officers could be occasionally recruited from (elite) crew.