This is something that has bothered me lately with YouTube. As the article explains, tends to be inappropriate, sexual or mischievous. However not only that they tend to be cheaply made or make egregious copyright violations, most of which barely pass as "educational content" because they a child shouts the name of the color every minute or so.
What really bothers me however, is this type of content tends to be some of the most watched content on YouTube outside of music videos. For example, to give some context on YouTube performance, in the last 2 weeks, the most watched video on YT (according to our systems) was 'Luis Fonsi - Despacito ft. Daddy Yankee' with 300M views, #10 was 'DJ Khaled - Wild Thoughts ft. Rihanna, Bryson Tiller' with ~70M views. I think everyone would agree this type of content is well recognized in pop culture.
Kids "content" starts up at #29 with 'Сrying Babies Accident! Bad Baby Playing Doctor and Learn Colors with Bandage / Nursery Rhymes Songs' (http://youtu.be/b6B0pt_dhe0) with ~40M views. This isn't "niche content" nor is the spread of it limited. "Сrying Babies Accident" is more well produced than the other videos I've come across but still has same traits - the same stock sounds, the same stock music, intercut with 10 second "educational" content where the a child yells out the name of a color (see 2:40).
This video 'Learn Colors With Soccer Balls for Children' (http://youtu.be/OY7ILLGvAJk), exhibit more of the common 'yt kids content genre'. Again the same focus on learning 'colors' (I've yet to see content that teaches something other than colors), but now you can see the recurring characters of this genre, name Spiderman, the Hulk, and Elsa. I doubt any of this content is licensed by Disney, but the guys behind this are likely making millions.
My absolute favorite has to be 'THE BOSS BABY Learning Color Funny Videos - Learn Colors For Kids Best Moments Tim And The Boss' (youtu.be/gZVFKXt5WeQ), which is just a clip from the movie Boss Baby. It starts off normal until the final scene where it pauses and a child yells the name of the color. What happens next is strange - the entire scene tint shifts (for example the main characters body is blue), the clip plays again and a child yells a different color (~10M views in the past week).
For fun, the most interesting I've seen is 'Superhero Gamezone' (http://youtu.be/amrkiS1Bjao) - while many of these videos have "older" characters that act out Spiderman and Elsa, this is the only popular one where a full grown man acts like a toddler with his son. No colors in this one, but the same Spiderman/Hulk characters along with the exaggerated facial expressions.
A lot of children watch this content. I can't pass any judgement on whether its good or not, but to me, the obsession with this content is strange.