All of this "alcohol is legal why isn't MDMA" shit is pretty pointless, people use the exact same justification for Cannabis (which happens to have much less potential for harm from use) and it is completely ineffective. In case you haven't noticed, drugs are illegal. All of them. Or at least that's what governments would generally like to see, any psychoactive substance that reaches a certain "critical mass" in terms of its use is jumped on and scheduled, regardless of pretty much any other considerations. If it has a medical use it will be legal for that but still illegal to possess otherwise, because all recreational drug use is deemed to be bad and is pretty much universally illegal, at least with classical drugs.
Is this bullshit? Yes, I'm of the opinion that full legalization is the best course of action (decriminalization at the very least), as there's a funny thing about drugs - that being that most people who would use drugs would do so regardless of their legality. I use and the fact that its illegal doesn't even phase me, I have a number of friends and they think the exact same way, I really don't know anyone who wants to use but doesn't because it is illegal. Having these things illegal forces it to the black market, segregates uses from the general population and tends to cut off support for them. It throws people in prison completely ineffectually and results in the supply being 100% a black market trade. When it's the black market there is no oversight, morals can fall to the side and you end up with people getting hurt or dying. I'd go so far as to say that a very large number of deaths/injuries resulting from E use were not actually from MDMA, rather the adulterants that were in addition to/took the place of MDMA. Effectively the very laws that make it illegal to possess drugs are indirectly responsible for a large amount of the harm that is caused by drugs.
tl;dr: Drugs being illegal is a pointless endeavor that results in only harm to society, and the view that recreational use of drugs is bad is extremely dated, and is something that we as a culture really need to get past.