To be clear, I'm not actually saying this is all the fine. I think there are discussions to be had about the obviously worldwide impact. However, the point that I'm making was that "nobody but SpaceX has any say in what happens" is not true.
Certainly people can complain that current international treaties, federal regulations and so on aren't sufficient, that the decisions reached by regulatory bodies were incorrect, or ill informed, etc. But first they should be aware those decisions existed and did take into account input from a variety of sources, and it's not just 'if you can get it to space, do whatever you want'.
Astronomers are in other countries besides the US... and these satellites are going to span the globe impacting everyone everywhere.