The fact that neurotoxicity MIGHT be caused from recreational doses of ecstasy is enough to make it a "hard drug" (stupid term) in my mind. Just because NIDA propagandists like George Ricaurte use bad methodology to reach questionable conclusions doesn't prove conclusions they reach can't be valid ones. Just as cocaine and heroin users are facing a certain risk of addiction, ecstasy users are facing an uncertain but decidedly serious risk of neurotoxicity which is in some ways worst than addiction.
If x action may or may not lead to y consequence, that does not preclude x action from being a risky action if y consequence is not completely baseless. Taking a risk which might not actually be a risk is still taking a risk.