Was Nadella trying to twist the word "open" in the context of an IT talk for his own benefit? Probably.
You mean "open" in that users, IT, and developers are all allowed to use it?
Neither I nor the article said "allowed".
Is someone keeping Linux and macOS sheltered from any of these groups?
Sure, capitalism and the free market is.
- Linux is free and people still choose Windows over it. I'm not saying it's better, but anyone can use Linux yet they don't.
- Businesses would rather spend their budgets on Microsoft/Windows licenses than use a free product.
- I'm sure they exist, but I've never seen a company (outside of graphic design and some IT departments) that used anything other than Windows machines for their workstations.
- While their network/web may run Linux, most business/productivity platforms run on Windows servers. You want to make sure your network stays up, use Linux. You want your employees to get work done, you use Windows. It's not the best option, it's the only option.
Also keep in mind that Nadella was speaking to CEOs and upper management IT, so he was speaking to a business audience. Linux barley even has a foothold, let alone a platform for business users outside of the IT department. You can argue why, or talk about how evil Micro$haft is, but people are still choosing Windows over Linux by huge margins. So what's more open in this context? Something that everyone uses, is familiar with, has at home and at work, or something when you bring it up, the person says, "What's Linux?"