Sure, that's how it is, and how it has been for a long time.

Can't see anyone forcing you to keep it that way. If you have a winner, you give people a reason to participate, and by displaying the winner, you improve the visiblity of the challenge.

Anyhow, it was just a thought.

Another: if the challenge is to be kept non-competitive, why does it run so long? If it's just a fun "shoot some images on this theme and show them here", why run it longer than a week? As it is, a person can check the challenge, think "nah, not interested this month", and then it's a whole month before there's something new to consider.