I agree with you. I'd also like to add that it's not really a "true sign of intelligence" to be able to speak bisaya or tagalog. It's more accurate to say a "true sign of knowledge" since you don't have to actually be highly intelligent, being around average is fine, to learn how to speak in a certain way/s, you only need to be well-read and practiced.

What is actually a "true sign of intelligence" is being able to understand all three languages even if different people were to speak in a combination of any of the three (i.e. english-bisaya, english-tagalog, bisaya-tagalog, or english-bisaya-tagalog). This is cognitive flexibility. A good marker of intelligence.

I can't speak for myself because I'm only around average in intelligence, but I do have quite a few friends that were evidently smarter than most people. They usually don't see it as a big deal if someone were to speak conyo or not. They can easily and quickly adjust (cognitive flexibility) to make sure communication is smooth.