The app's audience is children. The blog post's audience are professional designers and engineers. I am speaking their language. People build apps for a variety of reasons - I started off with this app just making it for my kids, until I decided to make an effort to find more users - and one of those reasons is to make a living off the time spent working on it. There is absolutely nothing wrong with hoping to be compensated for your time and effort, and that is why we must discuss user retention and monetization. These are not dirty or exploitative terms in and of themselves, they are simply tools used to measure an app's usage and current level of progress towards your goals so that you can react accordingly.

What is exploitative is the way almost all supposedly child friendly apps try to trick or corrupt children with ads and gamified purchases. My post comes out very explicitly against this, which I presume you read.

I did, and I do genuinely find your project (and approach) commendable! I'm sorry I didn't say that because of the focus of my comment.

I was merely responding to the kind of language you used to describe it. You call it the language of designers and engineers, but I'm sorry, that's not my language! To me, that is the language of commercial entrepreneurs and capitalists and they give me a gag reflex.

I would love for you (and everyone else) to be able to live in a world where you can pursue this kind of passion project without having to worry about “making a living”. The commercial and capitalist mindset is what's standing in your way.

This actually captured my intended point, which was expressed poorly and hastily. It's not my intention to twist or neglect the good intentions of the OP in designing an app for his kids, merely pointing out that some of the language read more sinister.