IP theft would be one reason. If a computer is stolen which has source code that could be a problem. That said, most companies just deal with that risk or their business is not so dependent on source code but services and support instead.
> That said, most companies just deal with that risk
They actually don't, sadly. Most companies limit the risk using non-competes.
It's very hard to secure code. If someone wants to steal it, they can usually figure it out.
It's much easier to limit their legal ability to profit from stolen code. Most companies don't have IP that's very valuable on the black market. If you stole Zoom's compression algo, for example, it would be hard to profit without openly starting a new company and violating your non-compete.
