I did not go to a US school myself, but many of my friends who did are saying that studying diligently and doing well in class negatively affects your reputatio

I did not go to a US school myself, but many of my friends who did are saying that studying diligently and doing well in class negatively affects your reputation.. and if you are doing any nerdy extracurricular work or go to a STEM camp, you are just doomed.. ) And then these people go to college, and cannot do simple multiplication.. I think this is not how it should be..