The author points out that you can caramelize your onions properly over the course of 40 minutes while preparing other components, washing dishes, etc. But tha

The author points out that you can caramelize your onions properly over the course of 40 minutes while preparing other components, washing dishes, etc. But that doesn't make for a nice tight recipe the way "Stir onions over medium heat until caramelized, about 10 minutes" does. Some people are going to read "Meanwhile, caramelize onions over medium-low, about 40 minutes" and think "Oh boy, what a complex and loooong recipe, forget it!" Inexperienced cooks may not be comfortable leaving the onions unattended, and if you get caught up in the football game you could end up burning them and wasting half an hour's work. So if you lie and say ten minutes, people are going to do one of two things: * Cook the onions for ten minutes and use them however they turn out. The recipe might be kind of disappointing, but I bet if you did the rest right, it'll taste pretty decent in most cases. Lots of people are bad cooks, too, so properly caramelized onions may be the least of their worries anyway. * Keep cooking until the onions are done properly. I end up doing this sort of thing all the time anyway, when a recipe says things like "cook chicken breasts to 165 degrees, about 3 minutes on a side" and other nonsense (you'd think boxed macaroni and cheese would at least get it right but even at sea level it comes out inedibly hard if you boil for the lower end of the recommended time). The recipe comes out right and if you know to do this, you're probably already used to the fact that recipes lie so you're not much bothered. In short: the incentives probably weigh more toward making the recipe look quick and easy. When your readers are skimming over half a dozen recipes online, you don't want to be the long and complicated-looking one.