If you take his comments in context to other ones hes made over the last year it's clear that he resents that Disney threw out the treatment for the sequel trilogy he wrote. Him providing this treatment and creative input was part of the deal he made with them when he sold the franchise and I think he was surprised they decided change the direction. Since we don't know what his original treatment was its hard to say what Disney kept from it and what they didn't but apparently it was enough to upset Lucas.
He's since apologized for the comments and I get the impression he realized that wasn't the best way to express how he feels.
is it me, or did they pull a Marry Poppins author thing on Lucas?