There is a coordinated attack on Coco Melon because parents/caretakers are being hyper irresponsible and not spending enough time with their kids and instead let the TV co-parent (but I also feel like the attack is happening because Coco Melon is unsanctioned). 

The attack on Coco Melon is weird when you consider that most of the media recommended as alternatives to Coco Melon has the same songs/video styles as Coco Melon (even Sesame Street has a few videos with the same songs). These alternatives are ultimately not the remedy! And very sure when the alternatives start becoming popular these alternatives will be seen in the same light as Coco Melon and whatever developmental issues a kid has will be pinned on the media (when the kid doesn't touch grass).

Kids will want to watch/listen to any media that is catchy. Coco Melon doesn't even have the catchiest version of some of their biggest songs, like Baby Shark, but they do repurpose the catchy part on their other songs more often. Also also, Coco Melon has been creating Youtube videos for over a decade and Youtube has made analytics available to viral creators for years now. Many content Youtubers also have access to the same watchtime analytics that Coco Melon is being criticized for using. This is the internet, any creator who has a large audience can fine tune their media in ways previously unimagined. But ultimately regardless of these tools, the audience will always have their subjective taste, as every individual has subjective tastes.

Subjective taste is how your child would always prefer you read them their favorite bedtime story on a frequent basis (if you do read them bedtime stories), they would want to sing and dance to their favorite songs. In some cases they will learn to prefer stories they see their parents/caretakers enjoy.

Spend time with your kids and don't have them watching content you have not curated from a device connected to the internet (even with your supervision). It's also only going to get worse because we are now at a time where kids content isn't being produced by sanctioned/publicly funded entities. Kids focused internet content was crazier before the algorithm discovered channels like Coco Melon (which were initially by independent creators who filled a void). Y'all ever saw the Disney wrap off cos play kids movies??   

Here's one of the videos that attacks Coco Melon.

https://youtu.be/YEFptHp0AmM