I'm basically saying you're overestimating the average developer's understanding of the running of a private DNS server at all. Monoids and endofunctors aren't actually difficult either, but they're arcane knowledge that most people don't have, so any statement that relies on average developers having that knowledge is a bit unrealistic.

Basically, I'm pretty sure I could apt-get install bind, but then I would have no clue what I was doing and I'm not entirely sure what setting up a zone entails. These problems are probably all quite solvable, but without the foundational knowledge, it's not 1/10.