Why do the biggest channels have little activity?

[daftpunkfanatic]

Just take a look at these channels:

http://www.youtube.com/user/TheOfficialS...ture=watch
2,760,479 subscribers
875,959,575 video views
He does 1 or 2 things a month on his feed.

Madeon
http://www.youtube.com/user/itsmadeon/feed?filter=2
He's never commented favorited, or "liked" anything, All he's done is upload and upload and continue to get views.

http://www.youtube.com/user/officialpsy/feed?filter=2
We all know Psy, the artist behind "Gangnam Style". If you look, he has never really done anything but post post post, and sometimes create playlists. No comments.

Noah
https://www.youtube.com/user/NK5000?feature=watch
This is the man that took pictures of himself for years and made a compilation video. Guess what? He has two uploads and 28.6 million views, along with 11,929 SUBS! He has also never commented or liked anything.

Cinemassacre
https://www.youtube.com/user/JamesNinten...d?filter=2
Never likes, comments, or uses Youtube casually. Only uploads. Has
934,083 subscribers
423,867,832 video views

Finally, Jabup
https://twitter.com/jabupmusic
https://soundcloud.com/jabup/
https://www.youtube.com/watch?v=Zlv8LWvvNQg (Mis-titled, actually a Jabup song.)
Even goes about to say that he will do an interview, but he will only do one!

As you can see, for some odd reason, everyone on Youtube that is popular has an unusual quality about them where they:
- Never Comment
- Barely Subscribe to anyone
- Barely Favorite or Like
- Keep under the radar
- Have very little casual activity
- Never leave negative feedback
- Never pick fights

That is just my take on it on. Why do you think that the biggest Youtubers seem to be oblivious to the site?