I grew up in America so I just assumed the words were spelled that way so that is the way you wrote them. I was never taught of any reason for it, not in HS anyway. I took no English classes in college. Perhaps to be trendy, but perhaps for ease in spelling and while writing though I don't know. Could be that high and mighty sense America holds over the rest of the world too though! Anyway, I am glad they are spelled as such because my spelling is particularly bad anyway, any more difficult, and no one could read any of my posts! ;)