Why Removing Houses from inactive is NOT a solution.

[Syrehn]

Now pretty much all the housing is active players, and everyone knows if they unsubscribe for a bit they lose their house, which means housing owners are going to continue remaining active to keep their house, and fewer will be lost due to inactive relinquishment.

We don't actually know yet if the inactivity timer is going to be based off of unsubscribed players; that's pure speculation so far. SE very well might include players who haven't logged into the game (even if they are subbed) for x amount of days as inactive as well.