At more centrally-administered sites, a user might not even have the ability to change an X server option. The idea of making a toggle via xset sort-of makes sense, but seriously, isn't the idea generally that you trust the apps you're running anyway. And doesn't a vastly different wrong number in some X call at least produce an effect that makes you aware of the problem (I know, that doesn't make a X server more stable...). It's just baffling to make something near-universally available less so. The next new CPU thing could be bigendian - or quantum, but who knows what byte order that would prefer.