I think it's a good thing, or a good stage to be going through at least. He's no longer in the youthful denial of, "I'm doing fine, I don't have to work harder to succeed." He's now able to recognize that no, his study habits aren't good, and that's the direct cause of his mediocre grades. Now he's grasping at the last few straws he can find to try to still make it not his fault--"well, maybe it's my own fault, but it's really my
mom's fault for making it my fault"--and I think soon after this stage will come real acceptance of full responsibility. I hope so anyway, for your sake Ali.
My own brother turns 30 this year, and he's still in the "I can skate by and somehow everything will surely work out" stage.