I think web apps are a little unique because there's huge parts of them that are not content and that's where the separation of concerns originally came to be. I vehemently disagree with you that all of these things have to be entangled and tightly coupled. I think they just end up that way because it's the easy way to get through a problem and people who do things like that are, generally, lazy or on a tight deadline (for no reason that to have a deadline) or stressed or any number of things. Unfortunately, if all you're given is noodles, sauce, and meatballs, you're probably going to make spaghetti.