For one thing, lack of demand. Linux distributions can relatively easily ship different packages for different architectures, and doing so is more space-efficie

For one thing, lack of demand. Linux distributions can relatively easily ship different packages for different architectures, and doing so is more space-efficient. It seems to me like shipping multiple binaries within a package is mostly useful for the distribution of proprietary software, and even in that case, it isn't that hard to ship two binaries and a shell script.