It is certainly a sign of a capitalist society, but whether it is a healthy one or not is rather in dispute. Since the late-19th and early 20th Century, relatively pure capitalism has been broadly viewed as unhealthy in the places that have practiced it, generally replaced by the modern mixed economy which shares a common general shape of drift from capitalism in its various implementations, one aspect of which tends to be limitations on public officials engaging in commerce especially within the realm of their official responsibility, and Members of Congress (as well as the President) have, unlike officials of most particular agencies, an essentially universal domain of official responsibility.
Whether the legislation in place is sufficient to be the “appropriate legislation” on the issue is...rather the point in debate, an argument which simply takes that it is for granted and proceeds from there is missing the entire point.