The only trouble with spelling names a different way is that the person spends his/her life spelling it out correctly which is very tiresome. I always have to spell my surname out and often feel like saying "Smith" when leaving my name for booking tables etc. there's nothing wrong with different spellings but these same people/parents shouldn't take the hump if they are spelled the traditional way by mistake.
My Matthew is that way because the only Matthew I knew of was in the Bible and that it is how it is spelled there. Sylvia x