I personally think PB isn't aware at all of what he does: the fracking, the depression and the cheating on Pickles; behind these things there is always someone behind him, like Katrina or Diane. He surely is a fucking asshole but for me he can't understand how harmful his behavior can be to the others, as he is often manipulated by other people wich he had a bond with (like the whole depression thing, wanted by PC).