Another part of the loop is that many hiring groups also expect to see some public code out there. Maybe it's some library or widely popular project that helps your hiring chances or maybe it's just a toy project. None the less, you better have something sitting out there active for free.

Then, once you're hired and they're paying you, they certainly don't want you wasting their resources (paid time, IP) contributing free software.

The entire tech industry is morphing more and more into a dumpster fire itself.