Because it works really well for a corporate environment where you require central management for your devices. Yes, the environments of Linux and Windows are different as you said, and unfortunately that means one will generally be better than the other within certain contexts. The corporate workstation use case is a gigantic one that Windows is currently dominating in, and this is terrible for Linux adoption because it means to get a job at a place that uses Windows you are incentivized to use it yourself so you can learn it. It also means that schools (which are often run like businesses internally) are way more likely to use it, so new students that are just learning how to use a computer are coming up on Windows.
Linux is indeed very different from Windows and that's fine, that isn't a problem at all and it has plenty of upsides. What should be clear is that this particular use case is a remarkable downside for Linux, and the mass adoption of Windows in the majority of businesses should make that self evident. Realistically Linux can and absolutely is used in business contexts in the same way as Windows (hence why France is going ahead with it), but it isn't as optimized for it as Windows is, when it totally could be. Macs have had some robust management platforms made for them that I've found pretty similar to AD for example. If someone developed a straight out AD clone for Linux that functioned more or less the same on the front-end it would be huge for Linux adoption in my opinion. Hopefully that answers your question.