Those people who are familiar with a Unix variant are more familiar with Linux. Linux is different enough from *BSD that what people do learn about Linux doesn't translate.
Linux entry level is actually easier than Windows these days. In fact when I look for candidates if they only have Ubuntu / Docker on their resume its trash.
What used to be considered entry level skill sets are now called "Michael Jordan" level skillsets ( kernel compile / tuning , C debugging etc etc )
Currently I use Linux because it makes me money. I use the BSD's because I like them
I hope there's some wiggle room in there for folks who may know more but cater their resumes to what they want to do and/or the buzzwords recruiters are filtering by.