I've heard it pointed out that GHWB has only made pronouncements like this one where, instead of actually praising the things his son does in his policies, he merely shows disapproval at those dissing him. Typical father standing behind his son stuff, certainly not past president supporting their successor stuff.

To my knowledge, neither his dad or mom have ever really made statements calling his presidency a success and agreeing with his actions. I don't have the source of the quote so this is pure hearsay but I know I heard Barabara Bush as being quoted something to the effect of, "We were pleasantly surprised George became president. He was always the stupid one."