I also don't understand the claims that it doesn't generalize. I currently use it to solve problems that I can absolutely guarantee were not in its training set, and it generalizes well enough. I also think that one of the easiest ways to get it to generalize better would simply be through giving it synthetic data which demonstrates the process of generalizing.
It also seems foolish to extrapolate on what we have under the assumption that there won't be key insights/changes in architecture as we get to the limitations of synthetic data wins/multi-modal wins.