You very rarely ever hear a candidate saying the following, "John and I agree on just about everything, I think the people in this area will have a good representation regardless of who they elect".
The problem isn't that we don't hear
candidates say that. The problem is that we don't hear people who are already in office saying that. Incumbents can get away with that sort of thing, being incumbents. They can say "Candidate X's hissy fit makes little sense. We agree on this, that, and the other very important things. We merely disagree about foo. I have x years experience in this job and I have done y and z to support my constituents." and still get re-elected.
They don't have to be fire-breathing assholes, but they are. I would be too, if that's what the conventional wisdom said I had to do to get the cushy job.
Challengers probably should be fire-breathers. We need that energy to keep from ossifying. However, once elected, our representatives need to get it through their thick skulls that they represent all of their constituents, not just those they are most closely in agreement with. If you feel like your task is to radically reshape society, you're probably doing it wrong. As much as I'd like my "side" to be able to dictate to everyone (not really, the Democrats are waaay too far into Wall Street's pocket for my taste), our system of government was designed to run on consensus.