What does YouTube think it's business is?

From my pov they are an advertising company, they want users to spend as long as possible on the site inorder to view those ads.

I can sort of understand rewarding regular uploads from that pov, a new video by X comes out, you go to view it and then watch a few more videos.

This model doesn't explain other things though. If I find a new channel and want to binge, why stop me watching from oldest first?

Why remove downvotes? If I watch a video that has a lot of invisible downvotes, I get pissed because it's rubbish, it seems a toss up whether I watch another vid, or leave the site. That risk rises exponentially with every rubbish vid I come across.