It’s an appeal to the authority of credibility. The more you speak through the language of results, the more credible you are. It’s this appeal to credibility that people rely on when they choose doctors or lawyers.
You say it like credibility in those two contexts are a bad thing.
Doctors and lawyers are about the only occupations where a professional’s mistake could cost a client his/her life. No other professions come close, which is part of why the training is long and the practitioners require a license to practice.
