Yes - not enough people are watching to justify the cost.
But cancellation has a whole raft of hidden costs:
1. Reluctance of viewers to invest time in the next thing that comes along
2. Users defecting to rivals out of anger
3. A negative effect among those demographics that tend to influence others the most
4. Loss of creative talent - edgy directors and actors won't want to risk your platform
I'm sure there are more but they all circle around a common theme. Loss of trust.