How is that relevant? Linux isn't used by many photographers OR businesses. It's seeems to be a hobby all to itself, or a religion.
As Matt said, it's used a LOT in business. Just because you don't see it doesn't meant it isn't there. Of course, what do I know having spent the last 12 years delivering security services that rely on Linux to a large number of global customers.Linux is at the core of a huge percentage of the servers out there - including the ones that are using proprietary (not Open Source) software. A lot of businesses are relying upon it, in one version or another.
And as for Mac, it is very prominent in the educational world. It still has its devotees in the graphics world as well.
And of course, it is extremely well connected to the cel phones in a huge percentage of photographers' pockets.
Also, Linux is used as a host OS in Cloud Services from AWS, Microsoft, Google, and others. It's also used frequently in "network appliances" where its true nature is hidden behind a custom UI.
BTW, Android is based on Linux.
As for @Sirius Glass's assertion that Mac is best, I'll counter with all OSes suck and no one is best for all purposes. Here at home, we have machines running Linux, Windows, and ChromeOS. I've used OSX in the past, but didn't find it as useful to me, so I ditched it (actually, installed the old PowerPC port of Linux on the machine and ran it as a server for a few years).