New(er) posters might not be aware (and why would they be?) of the Boards' history and why this leaves remains of a demand for rigour in politics discussion. There was a time when these discussions could feature real experts in niche fields, wielding significant knowledge with specialist lenses.
This is far less the case now (though the levels of expertise you might stumble across from time to time can still surpass anything found elsewhere) but longer-term posters may continue to have little patience for superficial, banal or ignorant assertions.
I agree that rigour and politeness are not mutually exclusive, but I also understand the frustration with how the dumbed down nature of internet discourse has infected even here.
So, a plea from me (which you are all free to do what will with), match the tone of your posts with the level of your expertise. Tentative opinions should not have the same air of certainty as knowledge informed analysis (although the best of that accepts a loss of certainty too).
I know I'm an old man shaking my fist at the sky, but I'm going to shake that fist anyway.