There are two types of people in the world, those who get insulted by bad writing and those who don't even notice it's bad. Most intelligent people enjoy intelligent things, and likewise most stupid people enjoy stupid things. There are outliers and statistical anomalies, but I've found these generally hold up regardless of race, culture, background or age throughout the course of my life. It's a rare person who has an educated perspective in addition to having the capacity for critical thought - and lacking either of them will result in feedback meant to be discarded.
So whether or not OP's claim of "My friend is really smart! I know him!" is accurate or incorrectly evaluated (what I suspect) isn't really relevant. That's one (unproven) example amidst a sea of contrary information.