I'd be curious to know how many additional "wanted" recommendations the system is able to serve by not treating a dislike as a strong negative signal. It seems

I'd be curious to know how many additional "wanted" recommendations the system is able to serve by not treating a dislike as a strong negative signal. It seems like there's a tradeoff here, where YouTube figures that if it interpreted a dislike with a heavy hand, it would also knock a bunch of videos you do want (or at least they think you want). Presumably from YouTube's perspective, it's more important that your recommendations pane contain at least one video that you want to watch than it is that it contains zero videos you don't want to see. The user's desires are a probably a little more balanced - seeing videos on topics you dislike is annoying even if you don't watch them, and even if there is a single good video mixed in.