reasoning would be nice

OP covered it in the last section under "Gold Spammers". Essentially loot farmers and a shady black market will find a way to circumvent any restrictions. Once you let that monster loose, there is no good way to control it, unless you kill it for good. I did hear one decent argument where the rules were: - limit it to items only - limit it to items of the same type/rank (exotic arm for exotic arm for example - so trading is always a zero sum game) - no glimmer in trades (op covered this...but really glimmer is useless after level 10 so its a minor point) - only allow it between players on the same fire team, and [i]only[/i] in the post game lobby after a raid or crucible match. (Farmers are less likely to actually complete a real portion of the game with you to make a sale - they probably still would though if you were offering them real cash) This would be very difficult to make happen, and would likely be called a "nerfed" or "half-assed" trading system...drawing more criticism that it is worth to implement. From there it's basically "Buy your way to Legend".

easy RMT fix...make it so you can only trade exotics for exotics etc...

Agreed. Zero sum trading would level the playing field. In that case a gold farmer would have to basically [i]stock up[/i], and their sale prices would be [i]deflated[/i] based on the [i]tradee[/i] having to give up something of equal value to the [i]trader[/i]. Doubt that after the time sink to build their stock and the low price they could sell their "stock" for that they would even find it beneficial to spend time in this game versus a traditional MMO (like WoW or FFXIV). But say the two of us would easily be able to work out a deal where you hand over your Hawkmoon that you have no use for, but I purchase and hand over a Red Death that I don't care for. We both walk away with exotic weapons and are both happy. I guess I would vote for it. Given those conditions.