This is a feature and I love it. I don't want to subscribe to football channels, for example, but if I'm in the mood I watch a couple of them and then it shows me related videos for a few more hours and then it switches when I decide to search for cooking videos, of which I don't want to subscribe to either. Works great.

They could easily let you accomplish this by just giving you an option to actively seek out this content by giving you a "What else is like this?" button that takes you to a 'related videos' page.

The problem when it just puts it all in a single recommendation feed is that that feed more-or-less presents itself as "here's what the world is talking about" rather than "here's a bunch of stuff that conforms to the biases and ideological filters of the stuff you've been watching lately." It creates a solipsistic worldview if you're not aware of what's going on.

There needs to be a plugin to wipe cookies on every YouTube page load. The recommended videos list for a given video on your first visit? Excellent. Every subsequent page load where they give recommendations pertaining to a video from 30 minutes ago? Absolute garbage.

You can reject the recommended videos and purely exist either checking subscribed channels or using the search function for every video. I've found that their recommendations are usually pretty good but I use youtube on different devices for different "moods" so I've got my background lets-plays on one device - people talking about maps on another device - and my youtube-only music needs on a third device - this helps keep my stuff pretty siloed.

Curiously, I don't have that experience at all. I'll play Backyardigans videos to watch with the baby ~4 times per week and nothing of the sort ever shows up in my recommended feed. I can't understand the reports of sub-par recommendation experience on YouTube. Maybe my behavior is somewhat different -- I tap "watch this later" a lot (and rarely do).