Fair dinkum. These blokes are paid hundreds of thousands of dollars to be athletic sportsmen. The expectation is that they will eat right, excercise right and keep their bodies in optimum condition. Taking recreational drugs impacts on the condition of their bodies. No one is forcing them to play sport for a living. No one is forcing them to accept $100k+ salaries. If they want to use drugs they can do so but don't be an AFL footballer.
They live a priveleged lifestyle that sets them up for life. Forgoing recreational drugs, alcohol, take out food is a sacrifice that is required in return. I can tell you that if my employer offered me a $100,000 pay rise if I stopped drinking and occasionally doing recreational drugs it'd be an easy decision. They want it all their way.