Oh, another battle of the definitions, wonderful.
Instead of reading reply after reply untill my eyes start bleeding, I've decided to write a response, which is as neutral as possible, until the point where I start throwing in my own conclusions and assumptions.
What we can agree on:
Racing in cars is about getting to the finish line first, and requires control, speed, reactive skills and insight into many situations (perhaps this can best be described as experience, but whatever)
Drifting is (in most cases) about causing the car to oversteer, and controlling this oversteer throughout the corner to create a sort of showy display of skill and control, plus all of other other things I have written down under racing, except speed.
Now, let me elaborate on that last sentence. Many people will say that speed is also a part of drifting, and I won't disagree, but I would say that the slower the drift (or the less power of the car), the more skill is required to drift. In fact, even the drift king himself said on several occasions that it's not much of an art of drifting a high-powered RWD car, but that drifting a low-powered car is much more difficult and a much better display of control.
Now, I enjoy almost all forms of motorsport, but what I definitely do not enjoy is some guy in an 800bhp Supra, spinning his tires throughout a corner and generating more smoke than noise. What I do enjoy is a person in a relatively low-powered car, carefully controlling and manipulating the car in a 'clean' drift. That's what motorsport is about! Mastering a motorised vehicle and controlling it to the limits, but that in itself is not necessarily racing!
A fairly accurate definition of racing is: "The sport of engaging in contests of speed" with examples of such races as: "Auto racing, boat racing, horse racing, car racing". This all sounds fairly logical, but drift-racing is not in there.
I understand that drift competitions which involve overtaking can be seen as racing, but it's completely and fundamentally different from regular car racing. There's completely different basic rules for every aspect of the game, it's like apples and oranges.
If you compare any form of racing to each other, you'll always find the same basic rule: Whoever gets to the finish line first wins.
The basic rule may be supplemented by sub-rules which refer to the vehicles used, pitstops required, etiquette for certain events, whatever.
In drift-racing, part of the main rule is that you absolutely have to drift. Therefore it does not fit with the general definition of racing, as speed is not the main rule. After all, if speed was the objective of the competition, why would you cripple yourself by forcing a rule in which you have to go sideways? It's definitely not the same as the FIA deciding that there should be no V10's in Formula one, as the rule applies not to the vehicles used, but the style of controlling the vehicle.
So what I think is the matter here, is that certain aspects of drift can be seen as a race in that it is a competition in which speed plays some part. However the word 'drift-racing' feels a little off to me. It's like saying: "slamdunk-only-basketball" or "one-armed-waterpolo", like a forced handicap which deviates from the original sport.
I suppose that's my final conclusion, drifting is a branch of autosport, but I see no way that it could be seen as a pure form of racing, per definition of any good dictionary.
Flame on!