When I first began playing it was doing port trading, shared trade, so resources such as wood, rum, etc. I am now main-time fisherman/whaler, and I still do port trading when I travel down south to sell whale oil. I will often stick around for a day or two to do port trading. Port trading is mainly buying, selling, and travel. Though sometimes one must risk going into middle for better margin, but not always. If you are patient enough you can sell outside of middle with similar rates.
The imbalance stems from just how little loss there is involved with port trading. 99% of losses are repairs to upgrades from all the mileage. You also do not need to be flagged to trade, especially if you have help to overload. You're really only push space bar to dock really.
With fishing, and whaling, you run the risk of aggro and getting chased out of a hotzone where there is many fish or whale by imperial, or pirate nps. This is good intelligence. In trading, travel, outside of the player intelligence with middle, there is very little resistance. Forts, imperials and pirate nps will tack on a couple mins to your travel navigating around them but outside of that there really isn't much else.
For a player who really knows how to navigate the wind is hardly an adversary. There is limited resistance and intelligence involved in the risk management of trading to make it in-line with other play styles. There shoud be more intelligent nps endeavors involved to support anti-trade. This would obviously expand to offer more PvE encounters for players who are outside of trade but still navigating the same waters as well.