I think you are giving one random blogger a whole lot of credence.
HS kids are STILL encouraged to try different things. My kids did debate, softball (they were terrible players but they loved playing), yearbook, newspaper, a couple of school plays even with no talent (there is always room in a musical for someone to stand in the back and shuffle while mouthing the words during a big number), political clubs, volunteer work, etc. The HS kids in my neighborhood work in local businesses, play tennis, volunteer for local charities and organizations, play in the youth orchestra, perform stand up, rake leaves and shovel snow for elderly neighbors. Doesn’t seem like much has changed since my kids were in HS except for the ubiquitous phone and selfie taking.
Is this Harvard blogger a savant of some kind?