Why should a web architecture be loosely coupled?

Question

When I look at ASP.NET MVC projects I everytime see loose coupled architecture.

For what do I need a loose coupling in a web architecture (if I do not make unit test

Answer 1

Division of labor, which is the human equivalent of separation of concerns. Your HTML guru should be able to work independently of your SQL goddess.

A dramatic change to the front end should be able to proceed without tearing up the backend, and vice versa. In other words, you should only have to hire one person instead of two.