I work for a major enterprise software company. We can install whatever we want on our computers as long as we use full disk encryption.

Small companies usually. It helps being somewhere that runs a cross platform stack like Java and/or targets Linux servers anyway.

Once I'd been here a few months, they trusted me not to brick the laptop, they're fine with me installing Linux on a Mac if I say it works better for me and I can leave OS X on there as a dual boot.

Big companies are usually less willing, either due to some OS specific software or policies that enforce some specific encryption/security/monitoring.

Why not?

IT burden.

Weird, I would never imagine locking down development workstations -- how would you ever get anything done? Just one example would be Docker, having access is equivalent to root so why beat around the bush?

Our office basically treats development boxes the same as BYOD except the company buys the hardware. IT will do best effort diagnostics and recovery on those machines but otherwise you're on your own.

Eh I don't even necessarily mean locking stuff down. But having standardized images to roll out makes things simpler, keeping patches up to date, etc.