Yes, you're running a business, say a small one with 10 PCs. You could go for ten custom-built PCs with Linux. You'll be paying a linux support person to set these up and migrate your data, and set up your email. You've saved £1000 on Windows Pro licences, and you'll be saving money because of the lack of viruses, annoying updates and general reliability.
But you'll be spending money on (possibly) training, increased maintenance costs due to lack of knowledge of linux generally, and possible future problems if some new program becomes necessary and it's not available on linux .
Then you could argue that you wouldn't use apps that aren't web-based ("cloud" apps) anyway.
All these are part of making a "business decision" about whether to implement linux.
Personally speaking, I have tried to use Mac, Linux and Windows for my day-to-day work. All I require is the ability to browser the web, get email, run our support system and rapidly switch between these tasks on any computer I pick up. We use google docs so most of this is on the web.
All these things are possible with all three OSes, but I find that the last linux I tried (last year, Ubuntu with Unity) was too clunky for day-to-day use, and there was no google files sync, which was a slight problem only. Maybe the file manager could have been replaced with a modern one but I found it slow and clunky. I tried Windows and it's just too crashy and rebooty (does updates when you least expect). Personally I just preferred MacOS.
We have dozens of small business customers and support about 600 computers and even though I hate windows, I prefer MacOS, and Linux is reliable, I have not been able to recommend one single Linux PC to any of our customers. We do have a handful of Linux servers, that's all.