So true. I've worked in a lot of data centers, and seen the fighting and politics of management favoring one type of vendor over another, with multiple vendors in the same data center. Supported a lot of flavors, including WANG, IV-Phase, DEC, IBM etc. Generally the data centers with mostly Apples tended to be art studios, publishing houses, music studios and education centers. Strangely enough, one site where I saw a large penetration of Apples among other machines was in a police headquarters.
Apple hasn’t even made a rack-mounted machine since 2011, when it killed the Xserve. I’ve seen offices with Mac servers, but they tend to be small enough that the “server” is just a desktop machine doing file and print sharing.
The Xserve was aiming for companies big enough to need rack-mounted servers but small enough not to need an expert admin, and that’s a pretty small niche, which has gotten steadily smaller as cloud services have gotten more and more attractive.
The Xserve was also thrown into the fray in 2002, when there were a lot of server OSen — Unix was pretty dominant, with Solaris, Linux, and Microsoft gaining market share. It looked like a market OS X could take a bite out of. By the time the Xserve was killed in 2011, it was pretty much all Linux and Microsoft running on commodity hardware, and there wasn’t really a place for a premium-priced machine sold on its easy-to-use OS.