as long as blizzard properly oversees what you can/can't buy with gold i don't think it's cheating.
the fact that buying anything of real value in game, say 1m+ gold, by buying tokens is just not the kind of money the vast majority of people are able or willing to spend also helps a lot. (then again i do know like 4 people who buy tokens like candy, so maybe there are more then one would think)
now i will say that an unfortunate side effect of this is that in order to keep that deterrent barrier in effect, it does mean that things like e.g. the AH mount probably cost notably more then they would have in a world where tokens didn't exist, so tokens do lead to some level of discrimination between players. but again as long as its kept in decent bounds by blizzard, that's not the end of the world.