Here’s the first paragraph of Barro’s conclusion...
I see that paragraph as a list of effects to companies from the tax cut and expensing of equipment. There is nothing there that could not co-exist with a belief that corporate taxes were too low.
A better plan would have introduced full expensing fo fall forms of capital spending on a permanent basis ...
It sounds like his issue with the tax code is more about the expensing of equipment rather than the corporate tax rate.
i.e., more corporate changes.
I too am in favor of more changes to the corporate tax structure. That doesn't mean I think the corporate tax rate is high.