Well, it isn't really fair after all, you're running unhindered by footwear, and competing against all those other folks whose running technique is almost certainly negatively affected by their footwear to some degree....
Just kidding, competition should be about finding the best way for you to run naturally, without using any assistive devices that give you an unfair advangage. I wouldn't call running shoes, "assistive", but certainly bare feet are not assistive, their a natural part of our bodies. Obviously the rules are not reasonable, and rules should be based on reason, not ignorance.
Have fun,
-barefoot ken bob