No, they're fighting market inefficiency. A free market requires accurate and timely information to be efficient. This is literally people putting constraints on the market for what they are selling so the information is not available to one side, and the price is inflated.
A rational actor should walk away from a system like this, but if that's all that's available around you because of scarcity, you're forced to work at a disadvantage.
Banning this is akin to banning other anticomptitive behavior, such as collusion and monopolies. That is, it's up to the government to decide whether the harm outweighs the problems regulation introduces (regulation always introduces some level of friction and problems, you just hope to minimize them and maximize the benefits it brings) and is thus worth pursuing.