It’s as risky as giving a research presentation where you actually pay attention to font selection, color schemes, and composition.
I can’t quite tell if the author is being serious or sarcastic. I hope it’s meant in jest. I have never heard of someone criticizing, or being criticized, for having a had a poster or presentation that was “too pretty.” (If you have heard such criticisms, I’d love to hear about them in the comments!)
Beautiful does not mean dumb. It’s as true for posters as it is for people.
Don’t hate beauty