It's funny to see people complaining about the traders who have been WAY OP for far too long. I go back way before traders were put into the game, and they have been OP from the start. Try playing a multi-player server and have balance between those that use the trader and those that don't. It's not even close, the trader wins hands down. Balance between the traders and the rest of the game is an issue they will never fix.
If you want more balance with what ever systems you enjoy and want even more OP traders, you will have to move to mods like the rest of us.