Utilitarianism is broken because quality of experience is not actually a scalar value. It does not ideologically admit the possibility of the need for things like balance and rhythm.
Consider the fact that you can die of thirst and you can die of drowning. While you *can* reflect this fact in a utilitarian model of the world (the utility of water fluctuates over time) within a utilitarian ideological frame you will inevitably need to compute "the utility of water" which must now be zero.