Re: Obvious bull
Because you couldn't have possibly included (de)compression code for both algorithms in all versions of the OS, and you couldn't have possibly used an extra bit or byte in the volume descriptor or in the directory entries of files to signal which particular method was used to compress them.
And get more complaints about "Windows bloat"? Especially when there's more than one CPU instruction set involved. Windows NT supported x86, PowerPC and Alpha around the NT 3.51/NT4 days iirc, and developments of that system subsequently went to to Itanium, x86-64 and ARM (windows RT)