Because they would still have to build the plants somewhere, and the legal environment in the US is such that anywhere you build your project will be snowed under by NIMBY Lawsuits and your investment will never pay back anything. So nobody wants to try.
Can you give some examples?
> There are strict limits on what such lawsuits can do.
On paper that might be true. But the actual law rarely matches the law on paper.
https://www.powermag.com/how-the-vogtle-nuclear-expansions-c...
That said, I did not mean to imply that such lawsuits are the only issue that drives up costs for nuclear plants. From the article you reference it seems like various forms of government meddling in the process is a major factor, not to mention corporations being more interested in jockeying for position than getting a job done.
This is also true for the French project (Flamanville-3, an EPR). https://news.ycombinator.com/item?id=36258182