, if we compare your reasoning to heat and cold, I think it marks an inconsistency. In physics, cold is truly the absence of heat. It's a lack of motion of the molecules, so no infrared energy, heat, is emitted, as they're not doing their little dance. If all molecules would always be dancing, we would no longer be aware of the lack of heat, also known as coldness. That's true. But by the same extent, if never a molecule ever danced, we would neither speak of heat.
Even more, the absence of variation in conditions will also cause the perishment of the awareness of the state that does remain. Id est an ever warm world will not be called warm, because there's no contrast of coldness to compare it with. Similarly, an ever cold environment will not be called cold, because people wouldn't be aware what coldness is, since this is the norm. You need heat to become aware of coldness, and coldness to become aware of heat. There is no awareness of ying without yang and no yang without ying.
Although I would like to argue for the possibility of a society in which everybody chooses to solely do good, it not only is irrealistic, it would thus also undermine our awareness of what good is in the first place. Humanity would have to read up on old history books on our warring past to remain aware of good and evil, if ever such a society would develop.
Then still one can argue if goodness is not virtuous in and of itself, regardless of one's awareness of it. As William Shakespeare aptly wrote: "A rose by any other name would smell as sweet."