I don't understand that reasoning. Yes you are competing with other people, but for a reason. Reason being, during that time a lot more people are active and that is why the chances are much higher to have a high scoring submission.
Isn't your reasoning the same as saying you shouldn't play the lottery using "dates"? Like anniversaries or birthdays. So numbers 1-31 etc because that is what everybody plays and if you win you have to split the pot with all those other people? To me, this is ignoring the fact that a million dollars split between 100 people is still a lot more than zero dollars you get for yourself because you played different numbers.