I’m not sure “playing devil’s advocate” is a bad thing in and of itself if it is not in a public debate but when you’re having a friendly discussion trying to understand someone else viewpoint. I regularly play this role in a sincere effort to understand another viewpoint.

That being said, I agree with you if we are talking about a public debate where the goal isn’t to understand and think together, but to convince third party people watching a politician showdown.

(Is there different words for “real debate” and “rethorical/confrontationnal debate” in English ?)