It's a cliché, but it's true:
No one is immune to their own egos.
YouTube is, for many, a popularity contest.
Once you hear a person talking about using analytics and "finding the formula" for increasing viewership, increasing time a person sticks with a video, etc etc etc...
Growing the audience....
Well, you can't get more corporate than that.
My 2cents.
Passion/artistic expression should be the raison d'ĂȘtre...it should should drive the very creation of videos.
Many folks have it backwards, though, and simply adopt a formula that results in the the greatest "growth" of ___________ metric.