If I said "gosh, I can't believe you can actually think at a human speed, having to use words for everything! It's like having to speak out loud when you're reading, so slow! Have you been diagnosed by a professional on how to deal with this obvious handicap?" it would be pretty insulting, yes? Even if I said I wasn't trying to put someone down, because the implicit assumptions baked in to the very statements themselves.
All I can say is, as someone who also does not have an internal monologue, and can easily and happily go days without thinking in words (which is very, very different than not thinking at all), please just accept as a given that people like me exist, we're fine, do not feel like we have any deficits, and it's exceedingly frustrating to come across comments like yours whenever the subject comes up, because of the raw arrogance of it all. I can completely and honestly believe that you have a rich, engaging internal life, even if the quantity of words involved would drive me mad, because we're different people with different thinking styles. All I ask is for the same respect in return. If we can start there, then we can have a real conversation, which could be fun. I know that when I first learned that 'internal monologue' wasn't just a literary, poetically-descriptive term, but that people actually heard voices/words in their heads while thinking, it utterly floored me. That I'd made it to college without knowing this really threw me for a loop, and made me think about what other seemingly-core differences in cognition are out there. It really is a fascinating subject to think about.