[fusiongyro]

Sure. But AIX is something you are forced to use, not something you opt-in for. All the remaining commercial Unixes are kind of in that boat.

People my age and younger just didn't get much access to commercial Unix environments when we were growing up. Once we got into industry, we found it hard to see the justification for high Unixes when we had experienced good results with low Unixes. So the low Unixes have mostly won the war. This story repeats time and time again in our industry: the freest foo conquers the non-free foo, even if the non-free foo is technically superior.