Cassini was out of fuel, so no deep space thrusting possible. There was just enough to inject it into the terminal orbit set inside the rings, something believed so dangerous that it was saved for the very end of the mission. As it turned out, the space between the planet and the rings is remarkably clear, so all the orbits were completed. Either way, the intact craft or the pieces were destined to intersect the atmosphere, and we learned quite a bit this way while keeping the moons safe.
Anyone seeing shades of 2010 today?