In a letter sent out to Counter-Strike players in The Netherlands and posted on Reddit, Valve explains that it was the only way to ensure compliance with the new Dutch rules by the provided date of June 20th. The company clarifies that the loot box prohibition in The Netherlands is different than that of other European countries who have also banned the practice, such as Belgium. The company says it neither understands nor agrees with the legal reasoning, but Valve is out of time.
Disabling trading gets the company around a key statement within the Dutch legal study on loot boxes: "Loot boxes contravene the law if the in-game goods from the loot boxes are transferable," the study says. "Loot boxes do not contravene the law if in-game goods from the loot boxes are not transferable."
Valve concluded that the most practical way to comply with the new law was to disable trading, so that players couldn't transfer their loot box gains. It's an inconvenient solution, but the company promises to continue to research the issue to find a better way of dealing with the problem.