No, because the frontend doesn't have to be run on a server. The code could be open source and be run directly from your own machine or there could be multiple servers and multiple frontends hosting the service because all the relevant information in on the Hive blockchain; accessible to all.
Basically anyone who has the block information can host a frontend.
I see. And the code for the front end could contain the code for discovering all buy bids and sell offers entered on the chain as well. So anyone running that code on his or her local machine or server would present the same list of bids. Or could perhaps apply a filter and show only all bids for buying Hive or whatever.
Nice!