My question is more, why even try to use the same syntax for all architectures? I thought that was what GAS's approach was: that they took AT&T syntax, which historically was unified syntax for several PDPs (and some other ISA, I believe? VAX?) and they made it fit every other ISA they supported. Except apparently no, they didn't, they adopted the vendors' syntaxes for other ISAs but not for Intel's x86? Why? It just boggles my mind.
I don’t believe GNU invented the AT&T syntax for x86. System V probably targeted x86 before GNU did (Richard Stallman didn’t think highly of microcomputers). They used some kind of proprietary toolchain at the time that gas must have copied.
My question is more, why even try to use the same syntax for all architectures? I thought that was what GAS's approach was: that they took AT&T syntax, which historically was unified syntax for several PDPs (and some other ISA, I believe? VAX?) and they made it fit every other ISA they supported. Except apparently no, they didn't, they adopted the vendors' syntaxes for other ISAs but not for Intel's x86? Why? It just boggles my mind.