I think the article does a decent job of pointing out possibly problematic behaviors - that may or may not be connected to a particular diagnosis - and how they can be problematic.
I find the most useful thing about the article is that it gives lots of examples of potential red flags in an organized way. It tries, and maybe does not always succeed, to point out behaviours (sometimes generated by diagnosable mental health issues, sometimes not) that can have, cumulatively, bad consequences. So it doesn't say to avoid sociopaths but rather, look out, analyse and, if necessary, avoid such and such behavior, especially if the behavior happens over and over in a pattern - which may or may not be result of someone being a sociopath.
I do think that if one already has good filters, has an handle on 'good' flags, and trusts one's intuition, then this article may not be that helpful. (See NYCindie's post above for example.)
However, lots of people, for whatever reason, don't trust their own intuition, don't have a sense of what is good, positive behavior, and have no idea what might be a red flag in a given situation. Sometimes, one's family doesn't model good behavior (Minxxa noted her own upbringing as being this way) or people are not encouraged to develop and rely on their intuition.