Knowing when to use and when not to use a tool is as important as knowing how to use a tool. That is why before learning the easy/magic frameworks I try and do

Knowing when to use and when not to use a tool is as important as knowing how to use a tool. That is why before learning the easy/magic frameworks I try and do things by hand so I at least understand what the tradeoffs are and what that framework is actually providing. I think a better explanation in this article would be to not use CoreData until you have hit the particular pain point that CoreData solves. You are almost always better off making a tradeoff that you understand than one that you don't.