My point (which seems to have been unclear, from a couple of replies) was that people equate "saying something which I expect to be interpreted as what I mean" with "saying what I mean."

Following on from that point it is also sometimes assumed that the lack of comprehension is actually a status transaction. High status people don't need to understand what other people are saying (when it doesn't benefit them) - and understanding too much can be a sign of weakness. In such cases incomprehension is disrespect.

The problem, of course, is that people also systematically underestimate inferential distance.

My favorite ambiguous piece of dating vocabulary: "I think we should see other people." Are you breaking up, or suggesting polyamory?!

Brilliant. I hope someone tries to use that line on me when we're breaking up just so I can tease them about polyarmory. (I'm of the opinion that there is no reason breaking up can't be fun!)