Your comment is absolutely spot on, I've known people forking GCC internally and beating stock GCC with 7% to 10% on an obscure architecture -- and legal prohib

Your comment is absolutely spot on, I've known people forking GCC internally and beating stock GCC with 7% to 10% on an obscure architecture -- and legal prohibited them to share the patch upstream. I've seen such things several times in my career and it made me very skeptical of people generalizing, like your parent poster kind of did.