[ska]

Point is, it very often gets you far enough. So you try it first, and only adjust when you have real evidence that this is not working for you.

Certainly in this scenario - the false positive rate is only important if the true positive rate is too low. It's not at all clear that is a factor.

[thirduncle]

So you try it first, and only adjust when you have real evidence that this is not working for you.

That's the whole point -- in order to find evidence that it isn't working, you have to start looking at the false negatives --

or that is to say, where the "light is not".