I believe if drifting is a skill to be used in a form of racing that could benefit from it. In the early days of NASCAR (1950's and 60's) the cars would "drift or slide" around the turns due to their suspension, limited tire size, etc.
I would not call drifting itself a sport, Drifting is a term to describe a move or manuver.
Next thing you know, there's going to be a term for gaining speed in the straight passages between turns... wait a minute.. i've got it.. ACCELERATION!
I don't drag race my car, I run in staged acceleration comparisons...

Does it really matter who did it first anyway? The Romans used to "drift" their chariots around turns, so maybe they invented it???