Temporary absences are way too common to cause complete loss of such an expensive investment. But so long as they ensure that if you lose your house, you get your money back (both plot cost and building cost) plus keep all furnishings and features (including ones that cannot otherwise be removed), then it would be reasonable.

I still think they'd need a longer time before losing it than they initially considered, though. (That initially proposed rule was that if you went 30 days without entering your house, regardless of whether you're active during that time, then you totally lose the house and everything in it.) A more reasonable version would be perhaps if you unsubscribe for 45 days or don't log in to the game for 6 months, you'd lose your plot (bur retain all its items and cost). At some point, though, people who have left the game entirely have to lose their lock on so many housing plots.