I wasn't necessarily saying that mining companies can't or don't ship their ores at all, but I suppose I would like if they were a bit more limited in their cargo range. IMO, even 4300 limit isn't that much of a loss. Limiting them a bit more would provide more incentive for the miners to SELL the mined ores to shippers instead of just shipping it themselves (unless they really want to).
Thus, the natural push of gameplay would be for the factions to do their intended roles, while still giving them flexability to do more (albeit at a less effective rate)
It already IS this way for shippers in that they have no mining bonuses. I'd like it if the door were swung the opposite direction a bit more, so to speak.