I mean you don't have to do it, you can have someone game to match with you :) But it seems to be a recent trend I've seen where you have to make yourself matchable or you aren't eligible for participation. I'm not saying I'm a fan! It can vary, depending on who else is participating.

I also think this is mostly true for multifandom exchanges only. For single fandom, I think the 'old' rules still apply.