Reading the article and most of these comments, I've concluded that no two people are using the word "abstraction" exactly the same. I don't really understand what the author's definition of an "abstraction" is. He seems to call a poor database schema an "abstraction misalignment"; is anything not abstraction misalignment? It feels like we're in an old-folks home where everyone is talking but nobody is conversing. Nobody is agreeing on what "abstraction" means. A better title for this article is "mistakes are expensive", or possibly "bad design is expensive". But of course then nobody reads it, because everyone loves to hate on whatever they've decided "abstraction" means for them.