Emphasis on needlessly. Some bluntness is a good thing, even if it makes people uncomfortable. The alternative usually is prolonged awkwardness and beating around the bush, which likely will make people uncomfortable anyways. Just get it over with like an adult. Don't drag an uncomfortable thing out or even risk people not getting the message at all the first time around.
The socially acceptable thing to do is wait for them to catch up but that gets old.
A article shared on HN recently: https://www.bihealth.org/en/notices/intelligent-brains-take-....
Don't get me wrong other intelligent people are on board with me during these episodes, and they are sometimes able to present their specific concern with the solution and that is valuable. I've been wrong before of course. On the other hand the "think of all the complexities" crowd just spout nuggets of wisdom like that until they are able to comprehend the solution, and that takes about 15 minutes in my experience.