They know it is relatively easy to attain a high GPA by taking a light course load. Success in high school physics is considered a sign of academic maturity and ability. Some technically oriented college programs will deny entrance to students who have not taken high school physics. College success for virtually all science, computer, engineering, and premedical majors depends on passing physics. College level physics is a required course for all of these majors.
Engineering is almost entirely applied physics.
College physics courses for freshman often have 200 or more students in them and can be impersonal. They move at a fast pace and have a high failure rate. Some colleges will not allow a student to take college level physics unless they have had high school physics. These studies suggest that students with a high school physics course score on average about one letter grade higher in college physics than students with no high school physics background. Students themselves typically indicate that high school physics is a significant factor in their ability to handle college-level physics material.