I seriously don’t understand why Apple won’t make server macs, with proper server features like IPMI, rack mounting support, virtualization. As a software developer, macs are horrible to work with.

Beyond the nightmare that is code signing and certificates (required even for debug builds), the physical devices are special snowflakes. Getting them to play nicely in a CI/CD system is really difficult. They often freeze or misbehave requiring physical access to fix. Also, if you want to target older OS X or iOS versions, you need to use an older version of XCode (that Apple makes really difficult to find) and an older version of MacOS.

There are many other use cases beyond software development, such as render farms, network storage, backup etc.