Companies see Mac products as more attractive for their workforce than Linux-based workstations. Having printers, wifi, other products seemlessly work, since Apple devotes time and money ensuring that, improves productivity, generally, and lowers costs in (in terms of Helpdesk staff and time spent diagnosing and fixing systems integration). So, developers and admins make use of what's offered, as it is a middle-ground between stability and functionality.

While it may have been a happy accident, it's a pretty big market.

Precovid, on any conference I went to, professional or academic, the amount of Apple laptops was insane. I'm sure they're running things locally or on Linux servers, but the fact that they work pretty well between them is important.

For anecdata, I've worked at two companies in a row now that have used exclusively Macs because it's simultaneously an acceptable platform for serious dev work and still user-friendly to tech illiterate interns.