I think some are being far too simplistic regarding the use of 'party drugs'.
Drugs used in a recreational sense have the ability to disrupt the chemical balance in the brain. Yes I know grog can do this, but drugs like cocaine do it far more easily, and even if used in small amounts.
The problem with it, is you don't know if this is you, until after it happens.
These drugs are a gateway to pain and misery for all involved.
Legalising these drugs is like opening a box, which should remain firmly closed.
It's a bit like saying guns don't kill, it's the people using them.