> Why would you ever remove a test ?

Because the cost of building/running/maintaining and generally just having the test around is higher than the value I get from the test. And because I still have unit tests on the public function that should catch issues. Really, I just wrote them to help me during the dev part. Every extra line of code is debt.

> And then you're losing hours searching in your 10k commit history the code that had been removed.

You're right, I said it was a possibility, but I don't do that, it's not worth it. It has happened twice so far I think that I wished I hadn't removed the tests. I bit the bullet and rewrote them, which is okay because of how rare it is.