"let it crash". The core idea behind it has to do with the fact that modern applications have a huge number of states that they can find themselves in. The more complex your application is, the more variables you need to keep track of everything. Eventually it becomes impossible for developers to predict all combinations of state that these variables will form. Once your app gets into an undesirable state, the best thing you can do is to reset it and start from a fresh, well known and correct state