The first person has a lisp-like personality. The second person has bipolar disorder. The two sort of resemble one another, but in the lisp programmer's case, they aren't doing anything really harmful to themselves or anyone else. They aren't hurting anyone, they aren't hurting themselves seriously; they're just acting a little quirkily. They might be bipolar-like, but they don't have a disease like the person who goes on cocaine binges and then tries to kill himself does.
The same principle applies with ADHD. Some people literally cannot sit still for a minute, and will disrupt every class they're in because they simply cannot pay attention to the work. This behavior is a problem for themselves and others. However, most people have some trouble concentrating on things they find boring. It's practically tautological.
The problem is, when we start using medical disorders to describe personalities, we conflate the two. Suddenly, everyone has a disease. This isn't a problem in itself, but we tend to try to fix these diseases with medication. If we try to give every lisp programmer some lithium to cure his bipolar behavior, he's going to become substantially less brilliant (lithium taken early on tends to knock off a few IQ points). If we give him adderall to treat his supposed ADHD, he might end up getting addicted to amphetamine.
I think we really need to accept the fact that some brilliant people are going to have problems no matter what, and they are fundamentally part of their personality. I don't think teaching a lisp programmer Python is going to make him write code more consistently and still write code that's just as beautiful. I don't think we can slice the "tortured" part of "tortured genius" off without cutting off some of the "genius" with it.