YouTube is plagued by low quality content with clickbait titles, descriptions, and images. Often they outright lie about the content. Any DIY is a crapshoot. Even if it's not a lie, often it doesn't work or it's actually dangerous. Videos with lots of downvotes is a quick and easy indicator not to bother watching the 10 minute video to discover if it's good quality. YouTube's intention here is clear: if one can't determine in advance when a video is poor quality, they'll be forced to watch those poor quality videos until they find a good one. This increases time on the platform and their advertising revenue.