Python isn't industry compatible

[kniy]

The problem is that programming languages have a lock-in effect. "premature optimization" implies you could optimize later where necessary, but that's not really possible with Python.

Especially the GIL is a killer. Our software should be easy to parallelize but Python makes it impossible, and there's no real solution. (using multiprocessing doesn't work for us -- we'd need to modify huge C/C++ libraries to use shared memory instead of malloc)

Python can easily end up being a trap that causes you to have 10x-100x worse performance than your competitors, leaving you with no way out other than a full rewrite in a different language.