Houserules are a sign that the rules themselves have failed.
I know you're just parroting Sawyer, but this is an interesting point of discussion so I wanted to address it. Note that nothing I say here particularly applies to cRPGs.
An obsession with rules and systems is, in my experience, purely indicative of a poor tabletop GM. The rules exist, yes, to provide a framework to play the game in, but they are *not* the point of the game.
This is because game designers are not omniscient, and cannot foresee every single possible situation a tabletop group could get themselves into. Most of the older P&P rulebooks (2nd edition D&D, oWoD, Shadowrun, etc.) had sections encouraging GMs to create their own rules for unique situations not because the rules had somehow "Failed", but because they simply couldn't cover every imaginable situation, and did not want to restrict the creativity of a good GM.
Of course, this doesn't mean that the rules are pointless and unimportant, but the attitude that a game has failed if additional rules are required is laughably myopic, and is indicative of either: someone who has never played a tabletop RPG, or someone who is a lousy GM who can only rote-follow pre-made adventure modules.