I will probably regret writing this post.
So perhaps you have seen these touchless toilets in airports. They flush by themselves. Exhibit A:
Amazing. Wonderful. Sanitary. See that button on the left? That flushes the old fashioned way. You need that. Because no matter how good the sensor is, how elegant your solution for activating the sensor, no matter how impeccably designed the sensor is, you are going to need that button. And when you need that button, boy, you really need that button.
The same thing goes when you are building an “automated” analytics system that hides all of the math and complexity from your poor user. You’re going to need that button, for scarily similar reasons.