Yes, it limits available jobs and probably doesn't pay any top salaries. But better than selling myself to people I don't respect.
That being said, at a certain scale or type of company centralized management, software support, and security risks mean "allowing" random people to run their own OS becomes difficult and risky. Lots of large older companies probably have proprietary software, too (thankfully more of this is becoming web based).
Yes, in theory linux is more secure and anybody who would want to use it is probably capable of taking care of themselves, but it is probably (at large companies) corporate lawyers and CISOs ruining the fun. And linux can have its own risks and dedicating a team to support (from a security perspective) them isn't economical for the what would be very small user base. Ye old big bank can't and arguably shouldn't allow it without an otherwise good reason.
Another user commented about how it's unreasonable to ask them to run CAD software in a VM, but this is exactly what (some? many?) companies ask programmers to do. It's especially goofy if it's a software company where that development is their core business.
That devs at a company use Windows doesn't mean they're forced to. Often it just means the designers also work on Windows.
Most designers use Figma these days, which has clients for Windows and macOS, and can be used fully in a web browser as well.
In my experience of the rise of macOS among developers, the biggest driving force was mobile app development and mobile web development because Apple refused to provide first party developer tools or emulators usable on other operating systems and made it intentionally difficult to run macOS on non-Apple hardware or in a VM. Previously macOS was largely associated with designers, not developers. This move also started blurring the lines more with designers making the move to development and (to a smaller degree) vice versa.
