The people of the community were trying to eliminate sources of unhappiness. They believed that if no one had any more or less than another, had the same amount of love for every person, then everyone would be equal and therefore equally happy. They didn't see the need for the advances that come from competition between people of varying abilities and with different interests; as far as they were concerned, things were perfect the way they were, and there was no need for any change.
The idea of "sameness" is addressed by the Giver when he explains to Jonas about why people had chosen not to have color in their lives. Sameness represents the lack of physical differences as well as the void of emotions among the population and the lack of the ability to invoke change in the society. By living as one homogeneous group with no highs or lows, no one can create an imbalance in the society. The people had recognized a long time ago that by doing away with differences in people such as race and economic differences, they could have more harmonious existence.