You seem to be assuming that it's the same people crying both ways. They aren't. The community isn't a hive mind, some people feel one way, others feel another. You can't please everyone, and so whatever you do, some people are gonna be salty, and quite vocal about their saltiness.
Part of the problem here has to do with the dumb way that they implemented a lot of housing furnishings. While all furnishings are unsellable once placed, many furnishings - particularly the "trophy" furnishings created from rare ingredients from difficult accomplishments - can't even be retrieved without destroying them. My FC has a Leviathan fountain, for example, that we were reluctant to remove when we were redecorating, in spite of the fact that it clashed with the new decor, for the simple reason that we couldn't remove it without destroying it and it had a lot of sentimental value. So, we pretty much just moved it to an out-of-the-way corner and tried to bury it behind other decorations. :P
If someone gets a house, they can use it to display the cool furnishings that they've accumulated over time. If that house is reclaimed by SE, presumably all of those trophies are destroyed. SE ALWAYS wants to bring lapsed members back into the game, and they understand that a player might be discouraged from doing so if they come back and discover that not only is their house gone, but all the awesome stuff they put inside of it. It'd be as if SE removes all your gil if you return to the game after a long absence, only worse. Because of the loss of furnishings, a simple gil reimbursement doesn't automatically make everything hunky dory.
All that said, there ARE ways SE could get around these issues that doesn't involve redesigning housing from the bottom up (which is something they really should do, but probably never will). If SE could arrange some way to save the furnishings, that might mollify folks. Along with the reimbursement, if they actually came back to the game they could rest easy knowing that as soon as they're able to purchase a new house, they can move all their stuff right back into it. That might not be easy, granted, if housing remains as limited a resource as it is now, but it's something; all their hard-earned crap is still there and ready to be placed, once they have someplace to place it.
I'm guessing, though, that SE's solution won't be this elegant. They will take the easy way out; a timer of some kind, I'm guessing six months. If you're unsubscribed for six months, your house goes "poof". Furnishings lost. No gil reimbursement. Just gone. If you're going to be away from the game for a long time and want to keep your house, you will be required to continue paying for your subscription. It's as simple as that. Even if circumstances prevent you from logging into the game for long stretches of time, even something as serious as military deployment is unlikely to be able to stop you from wiring SE money. By this method, if you leave the game and have no intention of returning, then you probably don't care about your house anyway. If you leave the game for a long period of time, but are planning to return and don't want to lose your stuff, you'll have an option available.