The general consenus I've seen is that 1) projects/code that enables MacOS to be emulated is legal, but 2) running MacOS VMs on non-Apple hardware is a violation of the EULA you agree to when installing MacOS.

So if it's on an Apple device (even one not running MacOS as the host) it's fine, otherwise it's a violation of the EULA, and something a business probably doesn't want to get tangled in.

Thank you!

I'm not sure why you are getting downvoted.

I personally wouldn't have any scruples using this for testing/building OSS, but I would also think twice about using it at my job.

To clarify, by simulators I meant: iOS simulators running under a Linux docker host.