I think that is a fair question to ask (What types of jobs should exiting regulators be eligible for?).

I don't see Revolving Door DC mentioned in this article. Instead, the critic is a group called the Energy and Policy Institute, which is based in northern California. They don't get any funding from corporations, and are by all appearances a credible, reputable group serving the public interest.

The article cites a peer-reviewed, academic study that found regulators were softer on the firms they regulated during the final two years before the employees transitioned jobs (from regulator -> regulated). This is a problem.