I believe they dont even accept new users registration at the moment.
The invitation system was disabled recently which means that anyone can register for a new C-Cex account.
Announced in this tweet on April 13th
I would rather have as many exchanges as possible as well. If I knew how to code worth a shit, I'd probably make a proper grc market myself (kijiji like or whatever)
I would also like to see GRC on a variety of exchanges.
Gridcoin has managed to trade enough volume on C-Cex to stay listed in the past, there has been a drop in trading since the GRC wallets were offline for several weeks after the version 3.7 wallet update but the volumes have increased again in recent weeks.
I expect GRC will continue to meet the volume threshold so long as C-Cex don't scare away too many of their existing customers with their new coin (de-)listing policies.