Well, the elders didn't do that. They gave Uchihas control under a police force, they let Uchihas be in ANBU, they even allowed them to be candidate to Hokage.
Uchihas only were sent apart from the village, because of the attack of the Nine Tails, people taught that was Uchihas fault (and it was, Madara did it), so, to protect the Uchihas the Hokage protected them, by putting them on a side of Konoha with no villagers, so they could stay safe.
But then they wanted to gain power and planned the coup d'etat, and Itachi killed them to protect the village he loved.