Because gaping mouth video clickbait is dumb. How often do you even see a video cover with someone having a closed mouth and normal facial expression?
There is plenty of space for quality and thought out content on YouTube. Especially if you don't need to make a living. The kicker to me, seems the extra time required to get production value to a tolerable point.
https://www.youtube.com/live/UAUg6y2UX88?feature=share
I stopped most of the way down the page. Here are the exaggerated facial expressions:
https://www.youtube.com/live/CN5bnEn9YZA?feature=share (sort of an exaggerated :|)
https://youtu.be/iQ190Bf-6J0 (the only actual “soyface” I could find)
https://youtu.be/fpnd1OboPPs (borderline soyface maybe?)
So that’s 16 normal facial expressions, four slightly exaggerated ones, and 1, maybe 2 soyfaces. And a much larger majority of videos that didn’t show the presenter’s face on the thumbnail at all.
Edit: It occurs to me now that it’s not that easy to see a YouTube thumbnail after you click through to the actual video.