There's a lot of nice Python code out there, mostly written by disciplined and experienced systems people.

But I agree about the hordes of data scientists making copy and paste spaghetti. This is evidenced by companies deploying Jupyter notebooks in production, which essentially witnesses the fact that they've given up on getting data people to write quality production Python, and instead they treat their prototype spaghetti as sandboxed blackboxes that can be tested on inputs and deployed if they perform well enough.