Piketty's argument - the one he puts forward over 700 pages in the book - as distinct from Piketty himself.
Saying Piketty is jealous may or may not be true, but it says nothing about whether what he says in his book is correct or not (and if not in what way he is incorrect).
If someone disagrees with what he says then saying things about Piketty himself is really rather by-the-by as it's his analysis that needs to be critiqued. He may be an idiot speaking truth or a genius speaking nonsense, but the truth or nonsense (rather than the idiot or genius) is the significant matter.
EDIT: I've not read either Piketty (life is too short - at least mine is) or Greenspun's analysis of it (would be rather pointless as I've not read what he's talking about).
I'm only saying that if something can be genuinely summarised as "Piketty is jealous" then that sounds like an attack on the author rather than the work.
Saying Piketty is jealous may or may not be true, but it says nothing about whether what he says in his book is correct or not (and if not in what way he is incorrect).
If someone disagrees with what he says then saying things about Piketty himself is really rather by-the-by as it's his analysis that needs to be critiqued. He may be an idiot speaking truth or a genius speaking nonsense, but the truth or nonsense (rather than the idiot or genius) is the significant matter.
EDIT: I've not read either Piketty (life is too short - at least mine is) or Greenspun's analysis of it (would be rather pointless as I've not read what he's talking about).
I'm only saying that if something can be genuinely summarised as "Piketty is jealous" then that sounds like an attack on the author rather than the work.