Because they've only dealt with the most simple of use cases, and have no idea that the world is bigger than their little circle. The classic signs are usually

Because they've only dealt with the most simple of use cases, and have no idea that the world is bigger than their little circle. The classic signs are usually upfront, presenting the product as the holy grail, in this case "The very last CMS framework you will ever need". Anybody with any experience knows that this cannot possibly be anywhere near true, not even if technology stops evolving altogether. You see this pattern nearly every day on HN. A language, a framework, a design pattern, a database, a methodology. Our industry is like playground for juvenile fundamentalists who all believe in the One True Tool.