At this point, I think we continue to use it merely because our cultural dominance coupled with a strange measurement system continues to irritate the rest of the world
Celsius is WAY more stupid than Fahrenheit, however. I like my temperature scale of 0-100 to be based on human tolerances instead of water's tolerances.
Fahrenheit:
0 = Really freakin cold, bundle up
100 = Really freakin hot, drink lots/strip down
Celsius:
0 = Rather cold I guess, probably want a coat
100 = You and everything else died dozens of degrees ago. Why even measure this high?