I agree that some level of ambiguity is unavoidable, especially on initial exchange.
Given iterated exchange, I usually find that ambiguity can be reduced to negligible levels, but sometimes that fails.
I agree that some folks here have the habit you describe, of interpreting other people's comments uncharitably. This is not unique to AI issues; the same occurs from time to time with respect to decision theory, moral philosophy, theology, various other things.
I don't find it as common here as you describe it as being, either with respect to AI risks or anything else.
Perhaps it's more common here than I think but I attend to the exceptions disproportionally; perhaps it's less common here than you think but you attend to it disproportionally; perhaps we actually perceive it as equally common but you choose to describe it as the general case for rhetorical reasons; perhaps your notion of "the interpretation that makes the least amount of sense" is not what I would consider an uncharitable interpretation; perhaps something else is going on.
I agree that fear tends to inhibit reasonable processing.