I haven't thought it through much, but wouldn't congressional term limits require a lot of changes to the way the congress currently works? Aren't there chairman-ships and whatnot that are assigned based on seniority, etc? Even if these rules aren't in the house rules themselves, would it be disruptive in the short term by forcing the parties to figure out new ways to deal with that kind of thing?
Also, it's an interesting question if they're better off with or without. Is a career politician more or less beholden to corporate interests than one who's explicitly looking for a new job in a few years? And how much time does that take vs. campaigning vs. actually knowing how to get things done. It's a pretty thorny issue, I think.