Chrono, the problem with rky's quote is that those things that he used as examples are bad examples, because they are unique. There aren't 50 team deathmatches, there aren't 50 chat systems, and although there are 3, maybe 4 portal guns, Space Guys was the best.
We already have a bunch of guns, and we really don't need a whole lot that are simply a different model, with some minor variable changes.