We don't dump garbage and sewer into the Merced River as was the practice in the late 1800's. It's an ugly eyesore. They've been there several years. Well, actually, since the flood. Controls of backcountry access have been in place for many years.
Trails are in the best shape they have ever been.
Visitor counts are way down from the high year of 1994, when almost 5 million people swarmed into the park. Annual counts are now down in the 2.5 million range, which relieves a tremendous amount of pressure on park resources. We don't graze huge herds of cattle and sheep, nor do we stake horses in the meadows as was common practice once. Some of the areas in the valley still have not recovered from the damage the sheep did to it over 100 years ago. I just don't see the desperate need for such drastic measures.