In my view it's both. I'm one of those "scientific" programmers. I've used type hints, just to learn it, but tend not to use them in practice. Bugs caused by typing errors seem to be extremely rare in my little world.

I've also programmed extensively in Pascal, assembly, and C. I get it about types. Don't forget C has 8 different types of integers that have to be kept straight. ;-)

On the other hand, I realize that any of my programs is but a little nub of code sitting on top of large and expertly maintained libraries. I'm grateful for whatever the authors of those libraries are doing to keep their sanity, and am not surprised when I see type hints in those codes.