Cryptic would just lose money that way. They would probably also open the door for lawsuits, since Cryptic wouldn't exactly be able to prove that someone had actually in fact payed RL money in exchange for energy credits. There will always be a demand for a "short cut", banning the buyers won't do any more against gold-sellers than jailing pot-heads does in the so-called and failed "war on drugs".
IMO, the only fair way to combat gold-sellers is to heavily restrict what trial accounts can do (no tells, no mail, no trading with other players in any way); and the only way to fairly get rid of the market demand for easy credits is for Cryptic to sell them in the C-Store. Other players would complain about it, but it would be for more effective at reducing the demand for gold-sellers than banning buyers would.
Heck cryptic can just spend 5 dollars buy the min amount of energy from each gold farm then not only bann the supply account the transfer the energy, but also go and bann the account that are doing the farming and give the supply account the items to sell
Currently cryptic and most MMO are only banning the salesperson account. The almost never go after the storeage accounts or the farmers accounts.
The farmers have nothing to lose with their salesperson account being banned, however banning the storage and the farmers account really get them
Sadly, gold sellers are a way of life and I doubt that'll change for STO or any other game.
There has only ever been one MMORPG that i've ever played that had 0 gold sellers (and still has 0 gold sellers).
That's Nexus: The Kingdom of the Winds. It is a 2D MMORPG brought over from Korea in 1998. I have played it since beta and still continue to play it. During beta, it had several hundred thousand testers but when it started charging to play, they lost most of the player base.
These days, the game floats around 2,000 concurrent players.
It has never had gold sellers. Reason why? Not enough players.
and I doubt there is another company other than KRU Interactive (and previously, Nexon) that would be willing to continue hosting a game with so little subscribers.
Moral of this post? Keep reporting the gold spammers and deal with it.