Since the moment you "enter" a house, you're inside an instance anyway, why not allow players to buy "apartments" that are small, medium, and large sized?

In many cases, players don't need/want an external house to decorate. They'd rather just have a larger space to make their own, and let's face it: apartments are TINY.

There's no reason we couldn't have instanced deluxe apartments or condos as an option instead of needing to wait for a plot to open up. No amount of adding new housing plots is ever truly going to solve the issue, unless they add so many that there's literally a plot for every single character created.

Given this is the case, it just makes more sense to move into more instancing for housing.