It's possible to construct a paperclipper in theory. AIXI-tl is basically a paperclipper. It's goal is not paperclips but maximizing a reward signal, which can come from anything (perhaps a paperclip recognizer...) AIXI-tl is very inefficient, but it's a proof of concept that paperclipers are possible to construct. AIXI-tl is fully capable of speaking, solving problems, anything that it predicts will lead to more reward.

A real AI would be much more efficient approximation of AIXI. Perhaps something like modern neural nets, that can predict what actions will lead to reward. Probably something more complicated. But it's definitely possible to construct paperclippers that only care about maximizing some arbitrary reward. The idea that just having the goal of getting paperclips would somehow make it incapable of doing anything else, is just absurd.

As for your hypothesis of what intelligence is, I find it incredibly unconvincing. It's true I don't necessarily have a better hypothesis. Because no one does. No one knows how the brain works. But just asserting a vague hypothesis like doesn't help anyone unless it actually explains something or helps us build better models of intelligence. I don't think it explains anything. Its definitely not specific enough to build an actual model out of.

But really it's irrelevant to this discussion. Even if you are correct, it doesn't say anything about AI progress. In fact if you are right, it could mean AI is even sooner. Because if it's correct, it means AI researchers just need to figure out that one idea, to suddenly make intelligent AIs. If we are only one breakthrough like that away from AGI, we are very close indeed.