Another reason to do this is to explicitly point out that what the other person means and what they are literally saying are incompatible. Whether this helps or impedes the conversation depends on how serious it is and how clear it was to everyone what was actually meant.
Example:
Speaker 1: "Pi has infinitely many digits".
Speaker 2: "So does every real number (e.g. 0 = 0.000....). What you mean is there's no way to write Pi with finitely many digits, in any basis."
What you mean is there's no way to write Pi with finitely many digits, in any basis."
pi=1 in base pi
... but that's not what you meant :)
Edit: I didn't realize this before writing the post, but what I'm referring to is The Principle of Charity.
Story
I was confused about Node Modules, so I did a bunch of research to figure out how they work. Explaining things helps me to understand them, and I figured that others might benefit from my explanation, so I wrote a blog post about them. However, I'm inexperienced and still unsure of exactly what's going on, so I started the blog post off with a disclaimer:
My friend said that it's a bad idea to do that. He said:
I interpreted what he said literally and basically responded by saying:
This was stupid of me. He didn't mean "claim that you're 100% sure of what you've written". He didn't mean "pretend that you're way more confident in what you've written than what you really are". He meant, "I think that it comes across as you being less confident than you actually are. And so I think you should reword it to better communicate your confidence."
I shouldn't have interpreted what he said so literally. I should have thought about and responded to what I thought he meant to say. (Although, he also should have been more precise...)
Thesis
People often interpret and respond to statements literally. Instead of doing this, it's often useful to think about and respond to what the other person probably meant.
For example, "If I interpret what you said literally, then A. But you probably meant X, so B. If you meant Y, then C."
Depending on how confident you are in your interpretation, you should probably respond to a variety of possibilities. Like if you're < 80% sure that you know what they meant, you should probably respond to possibilities that have at least a 5% chance of being what they meant. I'm not sure whether 80 and 5 are the right numbers, but hopefully it communicates the point.
Why don't people do this?
I see two likely reasons:
Practical considerations