Apple allows people to virtualise OS X as a guest OS on top of an OS X host OS, on Mac Hardware.
Both commercial virtualisation platforms of OS X (VMWare Fusion and Parallels Desktop) have very easy "Create OS X VM from Recovery Partition" functionality.
Apple didn't make it a pain in the ass - if you need patched ISOs to install, it sounds like you're trying to do something they specifically don't allow.
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Apple allows people to virtualise OS X as a guest OS on top of an OS X host OS, on Mac Hardware.
Both commercial virtualisation platforms of OS X (VMWare Fusion and Parallels Desktop) have very easy "Create OS X VM from Recovery Partition" functionality.
Apple didn't make it a pain in the ass - if you need patched ISOs to install, it sounds like you're trying to do something they specifically don't allow.