It probably doesn't have a large enough effect to matter, but I would expect that it would negatively impact the people you're trying to positively impact by using this metric. If you're careful with your words, a better typist, refrain from slang, reread your posts multiple times, edit out typos or inconsistencies or rambling thoughts, this type of vocabulary ranking would "hurt" you. But if you do that you're also probably the type of person to write longer more well thought out comments. So it's probably a wash to slightly "achieving the opposite of what you want but not really enough that you'd notice it" if I had to guess.
But if it is equally skewed for everyone, does it really matter?
It probably doesn't have a large enough effect to matter, but I would expect that it would negatively impact the people you're trying to positively impact by using this metric. If you're careful with your words, a better typist, refrain from slang, reread your posts multiple times, edit out typos or inconsistencies or rambling thoughts, this type of vocabulary ranking would "hurt" you. But if you do that you're also probably the type of person to write longer more well thought out comments. So it's probably a wash to slightly "achieving the opposite of what you want but not really enough that you'd notice it" if I had to guess.