With subjective relativism the line between doing what you think is right and doing what you want to do is not sharply drawn.
The case against Subjective Relativism
By allowing each person to decide right and wrong for himself or herself, subjective relativism makes no moral distinction between the actions of different people.
Subjective relativism and tolerance are two different things.
We should not give legitimacy to an ethical theory that allows people to make decisions based on something other than reason.