That (particularly in the context of polarising politics) seems worse; it's basically the sea lion meme. Just feels like a really disingenuous way of saying "I fundamentally disagree, but you should feel obliged to spend time justifying your opinion anyway because I've responded to you in this faux polite tone".
A polite tone also helps cover absolute dog shit nonsense arguments. You see it in the YouTube "debaters" that dunk on college kids. They keep a level head while college kids get angry. This hides that most of the debaters' "facts" are either opinion, out of date entirely, or just completely made up.
Polite doesn't mean acting in good faith. People seem to forget that.