I disagree with a good bit of this advice. And I suspect it varies with the discipline of study. In a field like computer science, time is better spent working on personal projects, hashing out ideas with peers and exploring research opportunities than aspiring to get an A in every class. A's make for boring, one dimensional students. People who make priorities based on more complex factors than an arbitrary letter g…
When I was entering college I thought this would be what I'd do in my free time. Instead, it turned out that all of my peers were disinterested in these sorts of things. I still did projects and research and decent internships while having an OK GPA (~3.9) but this definitely isn't possible everywhere.