Substitute house for rondo and the problem is solved.
Well, sure, if the problem is having Tony Allen and Rondo paired together on the backcourt, there's no problem if Tony Allen and Rondo are not paired together on the backcourt.
But I don't think that's the point. There is always a solution for everything: if your tallest center is 6'5'', you will front the post, fight the entry pass and problem solved. Well, in a sense, sure, it's solved. But even if there's more than one way to skin a cat, there still is a way that is better than the other.
Playing House will also mean that you'll lose Rondo's defensive prowess and distributing skills, for example. Playing your backup pg instead of the starter also creates problems that could be avoided if there wasn't the initial problem. And so on.
Fortunately, and watching the games since the pre-season, it's pretty obvious that Doc is going to address this issue (to not call it a problem, in order to avoid misunderstandings) in a more sophisticated and careful way than simply "put House in and problem solved".
More generally, and about the zones, teams can't play many pure zones because of the defensive 3 seconds rule, so those zones are generally used for short stretches to create doubt and confusion on the opponent (although some teams have used efficiently in the past for the length of entire play-offs series: Detroit vs. Chicago a couple of years ago comes to mind). However, hybrid systems, matchup-zones, box'1, weak or strong-side zones are becoming increasingly common. It's just a matter of time, as coaches and players get more and more comfortable playing them, until zones become hegemonic. Phil Jackson, traditionally an hard-core proponent of 1x1 defense, recently said that this season was the first one he was really trying to play zone. For the future of the NBA, man-to-man defense, barring further rules changes, will quickly become a memory in a few years, used very much like zone defense 5/6 years ago - by a couple of teams, for short minutes during selected games. And that's good, because zones promote better offenses than the 2 man game, post isolation and dribble drive style that became the norm in the NBA.