It's a significant disadvantage to have to own XCP in order to trade XCP/BTC in DEX. We are basically telling all new users to first go and purchase XCP (from others or a centralized exchange) outside DEX before coming and buying some more. It raises the entry barrier for new adopters. The system needs to be made simple for new users, not difficult.

I understand the serious issue of trolls. I didn't understand how miners don't have to pay fees to troll the order books and collect the fees but I take PP's word for it. A more dummies explanation would be desirable.