Tobold pointed out that developers have lame excuses against real money trading (RMT) of in-game items. Spamming, account theft and credit card issues are all linked to third party RMT that can be easily removed by sanctioned RMT. The game developer has so much control over the game and has so much more credibility than third party sites that it could take decent cut from RMT between players, just like Blizzard does with Diablo III.
Their claims don't answer the fundamental question: what's wrong with RMT?
I can pretty easily answer it, because I'm one of those who would benefit greatly from legal RMT. Both in WoW and EVE I could make significant real life sum selling in-game currency. In EVE, even with calculating with the current PLEX prices ($30/B) and my current income 40B/month, I could earn more money than the median income of my country. What would I do if RMT would be legalized in EVE? Quit my real time job and do EVE-trading instead. My income is limited by my trading time. Even with a very modest 330B/hour income approximation, I could make $10/hour in a country where the minimal hourly wage is $2. So hell with me trading in Jita, I'd hire some unemployed nerds to do the trading for me, according to my instructions and under supervision of course, pay them $6/hour and keep the other $4. With 10 employees working 8 hours per day, 20 days per month, I'd earn $77K/year without actually doing anything but check on my employees.
What effect would it have on the game? Every market fully covered, leaving no trading income to casual/newbie players, only similar professional traders could compete. The simpler income sources, like doing PvE would be covered by real world corporations using minimal wage labor (after all, ratting can be done by half-illiterates), leaving absolutely no in-game income source to the real players. The only way for real players to earn in-game currency would be RMT itself. However if the player can only obtain items by buying from someone, why should the developer give a share to me? They are better off removing farming completely and sell the items in the item shop, keeping the whole money.
The above happened exactly in Diablo III. The real players obtain 99.9% of their gear from the AH and don't farm themselves. It's not a tragedy in a one-time play box-sold game, but obviously a death sentence to any MMO.
To let real players progress, professionals cannot exist, so RMT cannot exist. Of course where is demand, there is supply, so if there is no official RMT, third party RMT emerges. To handle this, EVE is using a pretty good middle way: a limited official RMT. I can and do sell in-game currency for real money in EVE by buying PLEX and consuming it to fund my play. As I wrote on my birthday post, I fund 5 accounts for myself, 3 of it are training capital/supercapital pilots who may never be used. Add one more account for my girlfriend and that's it (supercapital pilots training for the Bazaar don't count, they are income source). 6 accounts, 3B/month ISK RMT-ed. I could sell much more ISK, but I'm limited by the utility of PLEX. What could I do with more PLEX? More accounts that I won't use?
Since I can't use more PLEX, I can't use more ISK, so I cut back on my trading, giving more space to other players to play in Jita. On the other hand that 3B/month I RMT away keeps several players in cheap ships for their $15, therefore stopping them being so broke that they'd turn to illicit RMT sellers.