The taking of Ecstacy is a similar concept to playing Russian Roulette - yes the chances of you coming to harm are small - but the harm you can come to is a fatality.
As with any street drug, you never know the strength and composition of the drug you buy, so what may give you a nice buzz one Saturday could fry your synapses to wazoo and back, giving you a fatal heart attack on the way, the next.
The notion that the fatality statistics make an argument for lowering its classification is as facile as working out how many children get killed playing 'chicken' on railway lines, and then saying that in view of the low fatality rate, it's an acceptable way for children to pass their free time.
You do have to wonder how these people are trusted to be out on their own without supervision, never mind making opinions that influence government legislation.