Weinberg points to some un-named Congressman for the line on finding priorities in science funding, but that's not necessary. He should be looking at his colleagues in a physics department, many of us feel the same way!
What particle physics has lacked is true oversight. At this point, their papers aren't really peer-reviewed, their grants aren't competitive, and their results are borderline relevant to actually understanding new physics. Their culture is so monolithic that they actually believe internal competition and review is all they need.
Astronomy is an example of a field of physics where oversight and competition have been beneficial. Weinberg is incorrect, we do not need space based resources to do the top level work. There have been some creative solutions to doing astronomy cost-effectively. Astronomers and the spin off field of cosmology have effectively taken leadership on research of fundamental physics away from particle physicists using small and moderately sized projects, with a few exceptions.
The social and funding effect which we're seeing now in particle physics can be found in any other big field of physics. Superconductivity research is famous for it. At a certain point, it's not really worth continuing fundamental research in a given field; funding and interest drops. It's not that everything is solved, but simply that creative research is no longer encouraged by the community and funding agencies get tired of seeing the same proposal every year. Eventually, more interesting research plans are accepted; funding and interest increases again. That will happen with accelerators, but first this old mindset needs to be challenged.