This can be done actually, if you imply registered users getting the remainder in the faucet.
However, the faucet has the benefit of forcing new users to install, learn, configure an ethereum wallet such as metamask. So as onboarding users into the network itself by being dropped xdai for transactions and a bit of honey. I think in the future we can move into a more guided/interactive method for this procedure, using something like quests.
But for now i don’t think we should do this. However, we may eventually do this with the current contract in order to terminate or empty it.