Fair enough on the Sleipnir, I don't play Rheinland, I just saw 5 gun vhf vs 6 gun vhf. But you just gave a major counter argument to your own point.
Quote: flying for a faction should also be motivated heavily by the faction's lore and one's RP intent
If people want to RP traders, they're still going to RP traders. Even though I despise it, I still log my Albatross or GAT to trade minor cargo because I feel like playing that character. If someone abandons their traders for mission grinding, then they didn't want to fly those ships anyways. Which is preferable; meaningful RP with people who want to be there, or people who just go "hi, get out of my way" to maximize their c/s? I've had more interesting encounters recently doing missions than I have trading.
PvE has been out for awhile now. You can look at the faction tracker and see that trading factions still populate the top of the list. Trading isn't dead, no matter how much you insist it should be. You'll still find smugglers too, even though ore trading is OP compared to how much you make on cardamine/artifacts/nox/whatever