I don't think it sounds healthy. But maybe writing tests is primarily a way to kill time? Like when I am not fully awake, I may not be able to concentrate hard enough to write some real code, but test code is less difficult.
The above isn't necessary an argument for TDD, but I think you might find it useful to try to view building a test suite and building your codebase as complementary activities rather than exclusive ones. If you use them together, the entire process becomes less difficult, and code in your test suite is just as valuable as anywhere else.