If you're working in a field which is positive-sum and produces a lot of good, performance enhancements of any kind make sense. The idea behind athletic competition is that it's just an arbitrary competition, so having all competitors agree to some restrictive rules (like no drugs, no motorcycles in the race, etc.) is worthwhile within the competition.

I'm fine with Elon Musk cheating as much as he wants to get a mission to Mars accomplished -- sending multiple rockets, using robots to make fuel, etc. If someone needs/wants Adderall to do good and is willing to take the health consequences, go for it.