Hmm. I just remember when the Intel assembler came out, thinking "whoa everything's backwards how irritating" so I guess ymmv. I'm guessing Stallman came from a pdp-11 background perhaps? The original (Ritchie) compiler emitted dec style pdp-11 assembler iirc.
Edit: realized that gcc first target was 68k so it would make sense for gas to use right way round assembler syntax.
I don't hate it because it's in src-dest order (though that does bother me). I hate it because it doesn't match the CPU. When you are actually programming something novel in assembly, you pretty much need to have the processor technical reference manual open, to be looking up those minute details that you can gloss over most of the time when reading disassembly, but which are so important to getting the most out of the processor when you're writing assembly. Or else you wouldn't be writing in assembly.
And it really, really bothers me when my tools do not match my documentation, for no good reason. (Just use the `-M intel` switch with x86 GNU tools, and then they will match. Or on ARM, do nothing, because by then they'd sensibly figured out not to bother with their "generic" syntax.)
When I ported my toy compiler backend from NASM macros to straight x86 instructions, as means to remove code I didn't own, I had this clever idea to use AT&T syntax because I wanted the compiler to depend only on GNU as and used the opportunity to try it out.
Never again, after all this years I still have vague memories of how I used TASM and MASM, and trying to write x86 AT&T was such a pain.
Edit: realized that gcc first target was 68k so it would make sense for gas to use right way round assembler syntax.