DC has tried to bring in new readers to the direct market certainly. But kid readers? Not really, no. Especially not in the last decade plus. With the exception of superhero TV show tie-ins and Super Sons, they really haven't tried anything that could appeal to that demo. Are these titles more successful in bookstores? Sure. But a lot of that is because often the message that people are sent is that kids are not welcome in comic book stores. I've seen some Comic Book stores do a wonderful job of making themselves welcoming space for families, but I've seen many more that make anyone who isn't a white adult male super uncomfortable. If you change the narrative, open the culture, and make monthly comics something for everyone, it could have a positive effect. And as you pointed out, since there is a market for these in bookstores, then making this attempt would already have ways in which it was profitable. Instead, DC cancels Super Sons and kills the momentum of the series and a potential way to welcome kids into the world of monthlies. There is no way in which that wasn't a mistake.