The problem is that you get a lot of guys who are good at academics who then construct their identity and life path around that without even considering how narrow and limiting it is. Because they are good students, they then decide that being a good student is the best thing a person could be. In the absence of more meaningful development they are stuck in a mode of receiving validation by way of getting gold stars from the teacher. They adopt a cargo cult mindset, worshiping "intellect" and imagining some distant future in which they will prosper at college and life without any real understanding of college or life. They have no experience at all of actual intellect, college, or life. All they know is that they like a couple academic subjects and have an uninformed and speculative mental picture of green grass on the other side of the fence. The media and the education systems share some blame here, propagating ideas about education offering more than it can actually deliver.

Reality tells a somewhat different story. High school academics are not particularly challenging and excelling at them isn't that significant. Honor roll certificates are meaningless slips of paper produced en masse from an MS Word template on a desktop printer. Being proficient at writing papers and regurgitating information isn't totally without value but is at least as much mere diligence as talent and a tiny and not particularly important subset of intelligence. Life rewards social skills above all else and guys looking to bank entirely on being more academically gifted than average are going to be in for a rude awakening. Life shares a lot in common with high school and college especially as it is mostly populated by young people directly out of high school.

By all means do your homework but a young man will get a lot more mileage out of physical and social development and should prioritize accordingly.

EDIT: It looks like I'm getting a more or less even mix of people agreeing and disagreeing with me. I made a post down thread that clarifies my point a bit and I will blockquote it here:

In the thread title I was exaggerating a bit for effect but I clarified my point in the OP. What I'm really addressing here is a particular type of special snowflake syndrome that can lead to stunted development. What these guys do is take a very narrow definition of intelligence and place it, and by extension themselves, at the center of the universe. And they do this with only the vaguest understanding of what lies ahead. Not to mention the eight years of high school plus college (possibly followed by grad school?) is a pretty long time to wait to start becoming a less lopsided personality. Worse still is that there are parents and elements of pop culture that actually encourage this sort of thinking.

The reality is that success, even academic success, is aided if not necessary by being more well rounded. Being academically strong can bring some benefits but should always take a back seat to physical and social development. It isn't that academics don't matter at all, but I want to take it out of the center of the universe and put it back in it's proper place.