Why is feedback inhibition important to the human endocrine system?

Because without the feedback inhibition we would have raging amounts of uncontrolled hormones.

Feedback inhibition is important to the human endocrine system because it tells the body that the response prevented the stimulus. For example if sensory receptors detect that there is a low blood sugar levels, the message will travel to the brain which will cause hormonal glands to release hormones, telling cells to release more glucose (sugar). Once the sugar levels reach normal levels, feedback inhibition occurs to tell the body that it has done enough already to increase blood sugar levels. If feedback inhibition did not occur, then the blood sugar levels could rise above normal levels.