While I don't necessarily disagree with the premise of the article, I am somewhat troubled by the tone.
If we were to take out "emotional leach" and replace it with "Blind", or "Paraplegic", or "Multiple-sclerosis", or "HIV Positive", would people still say this is great article? People with these disabilities are "leaches" in their own way. Each of these disabilities require more work on the part of the partner. Does that mean people should avoid getting into relationships with them? Just because you can't see an emotional or psychological disability, doesn't mean its any less of a disability.
That being said, I do agree that one should be cognizant of the symptoms of emotional/psychological disabilities, aware of the additional work/stress it places on the relationship, and make an informed choice if the reward of the relationship is worth the extra effort it takes to maintain and cultivate it.
Such relationships require the ability to put into place firm, loving boundaries. I am in a very close relationship with someone diagnosed with a Personality Disorder. My relationship boundary is that they receive therapy for their disability. If this person stops trying to help themself, I can't do it for them, and I will end the relationship.
Me: 48 - Married, straight, male
Shiela: My wife.
Suzanne: My FWB
Adam: Shiela's LDR