I mean YouTube UI is a disgrace really, what is it about big companies that stop them from being able to do design properly (even Apple post Jobs is starting to experience this).
- There are these weirdly looking fixed (Googleish) bars for no other reason than to steal my screen space.
- Recommendations are mostly awful (10 things that will shock you!) or videos I have already watched.
- The subscription to a whole channel is a dumb concept. I usually care only about specific series of videos, not the whole channel. Example: New movie reviews, not the bullshit rambling filler videos. The effect is that I often unsubscribe from the whole channel even though there is some interesting content.
- The video controls cover part of the video for no apparent reason.
- The volume control slider disappears for no reason when you move the cursor away from it.
- There are wrong defaults like showing annotations or autoplay.
- Annotations are abused so much that you cannot leave them enabled.
- Obvious missing feature: Next/previous buttons for videos that belong to a series. Playlists are used as a bad workaround.
- I can only use YouTube on my Desktops because that's where the ad blocker works.
- Obvious missing feature: Donations to content creators.
I don't think this is a big company problem. It is a culture problem. When your boss has no taste and does not take criticism very well, you end up with wrecks like Twitter, Google+ or YouTube.