I know first-hand of anecdotal examples where exactly that has happened, where people wanted to participate and chose not to for fear of something happening to them on a pecuniary basis in the future.
The obverse also happens. That places a limit on the skill that public servants are able to recruit as well. Don't only think about the individual who's a lobbyist; think about whom we want to attract into the public service. Whom do we want to be learning how to be politicians and becoming politicians in the future?
These are skills that are learned as they happen.