modafinil1
Like with any drug, abusing it is where the problem lies. He was taking the drug in a high dosage that created dependency. The same applies to any drug.
I take Modafinil intermittently, on occasions when I would benefit from it. I don't do so in a pattern that creates dependency. I do the same with coffee (i.e. avoid drinking it every day), and likewise with Alcohol - I drink when it's a suitable occasion, not every day. Similarly, I have smoked weed in the past, in moderate dosages, when it fitted the occasion and my lifestyle. It doesn't fit my busy lifestyle now, so I don't smoke weed.
I could have fallen into a pattern of Abuse with Modafinil, but that's the same with any of the other drugs I've mentioned. The usage/abuse pattern of the drug is the issue, not the drug itself.