I'm wondering why are so many people on ldl-lowering drugs when being so is not necessary?

Depends: The need for LDL lowering therapy should be determined after a sequence of events. First, conditions that may contribute to elevated LDL levels should be identified and managed. Next, the individual's cardiovascular risk and appropriate LDL target based on that risk need to be determined. If diet, exercise and these steps do not result in optimal LDL levels medical therapy should be utilized.

Hard to lower LDL.: A good number of people are simply not able to lower their LDL numbers through diet and exercise, despite maximal effort at such. Especially with the targets for healthy living getting lower and lower. Some people need to get their LDL levels below 70, and that's quite difficult to achieve without medication.