This is just insanely wrong-headed. Tests with no code are always negative value, the time it took to write the tests. Code with no tests might also be negative value, but it at least has the possibility of having positive value.
Tests are great and TDD is great for some people, but the whole point is to write useful software. It's important not to lose sight of that.
They may have negative value, but it is not a foregone conclusion. Tests are merely documentation and that documentation very well could provide positive value for someone who reads it. There is no doubt insights to be gained in reading about what someone was once thinking about a particular problem. If well thought out, you might even begin implementation based on that work, saving time having to document it all over again.
Tests are great and TDD is great for some people, but the whole point is to write useful software. It's important not to lose sight of that.