Musk is not accountable for Starlink. Starlink is an LLC, a limited liability company. There is no single person who is accountable for Starlink's satellites.
This article is more about the phenomenon where decisions are removed by multiple degrees. The locus of decision making is either obscured or non-existent, creating plausible deniability. This is often done by rewarding activities that don't obviously create harm but nevertheless require causing harm to carry out.
It's analogous to the Fox example in the article, where somebody at the top says, "we want high viewership." They don't want their employees to lie to their audience, and they don't force them to lie to their audience.
Does the Fox leadership at some point become aware that "lying to the audience" is a result of their performance goals, just like the decision makers at Starlink become aware that light pollution is a result of their goals? They very likely do. Does that make them feel accountable for the negative side effects? Probably not, because they didn't tell anyone to lie and pollute the skies, somebody else did that.