Thanks for the warning.
generally, lobbyists of economic interests do not inform; they misinform, motivated by self-gain.
No, you are confusing terms people use with the things those terms are used for.
A "lobbyist" is simply an expert one doesn't like.
Hence renaming them "zcars" would solve the problem.
You chose the term "the rotting corporate body of lobbyists" because you wanted the conclusion to be part of your argument so you can easily deflect criticism of your position by pretending that everyone you call a "lobbyist" or a part of a "rotting corporate body" is already acknowledges as a problematic entity by everybody else. That is just not the case.
It's as if I would claim that Obama's communists should not have any influence in the White House. You could say that Obama's advivers are legitimate employees who help the President do his job. But by calling them communists I have already won. I can now simply claim that YOU support Stalin and Mao, since you claim that the communists are needed for Obama to do his job.
The truth is that in order for a democracy to work, organisations that represent people MUST speak up and SHOULD be heard.
Without that, politicians simply make uninformed guesses.
If that is what you want, I still think you are wrong. But I suspect you are using the term "lobbyist" for anybody who advises politicians in a way you disagree with while those that advise politicians in ways you agree with are not the people you mean by "rotting corporate body".