The topic for debate is not about usage of drugs in sports, as the whole world would say no to that.
The matter of debate is the aftermath, like in the case with Agassi. This is not a first time a sportsperson has stated, 99% of the times in his autobiography, of using drugs.
Why do people do this? At least, in Agassi's case this was not needed at all. Why? Because according to Tennis Drug violation rules, "Performance-enhancing" drugs would constitute a Class 1, which would carry a suspension of two years. However, "crystal meth" which Agassi consumed would seem to be a clear case of Class 2; Recreational drugs.” That would mean a three-month suspension. Frankly, a 3 month ban cannot make a sportsman guilty enough to reveal it after nearly 12 years of the incident. Or another argument could be that he came up to reveal it just because it was for a 3 month ban; if he had consumed performance enhancing drugs, he wouldn't have revealed this.
All violations relating to drugs have been a very thin line between accidental vs intentional and it is your past record which would speak up for you. I think the officials believed him due to that or may be covered him up, which is so unfair to the sport.
The most ridiculous outcome in all this drama was something my friend pointed out to me :
"Times of India were waiting for some chance and they posted semi-nude pics of Brooks Shields and Steffi Graf in their column for discussion about Agassi's confession."