I’ve posted about this on here many times, but I see no problem with what the 14:10 “all in” runner OP is referring to is doing. There’s nothing quite like the running culture in high school and college, and, for most runners, college is the end of the line for being super serious. Might as well go all in and see how good you can be. Exercise science might seem like a fluff degree, and it kind of is, but it can also pave the way to physical therapy or medical school. Or, maybe this person wants to pursue the PhD.
Ultimately, it’s pretty simple. For all super serious runners, give it your all in high school, then college, and if you still have high aspirations, spend 2-3 years post collegiately chasing the dream and trying to PR and make an Olympic team and/or win some money on the roads. BUT, realize that this dream is over for 99.9% of us by age 25-26. And be realistic then and MOVE ON with your life if you can’t make a living doing it at that point.
25-26 is not too late to start a career or go to law school or even medical school. Basically what I did. I actually went to grad school to accommodate running but figured out by 25 that it was over, that I know longer enjoyed getting up at 6 am on Sunday to do a 20+ miler, that I needed to go get an advanced degree/career, and that I was tired of being skinny. So I stopped the quest, traveled, started lifting, and pursued my real career. Best decision I ever made. And I don’t regret any of it. I’m certainly don’t regret the years from 17-25 pursuing the running dream. But there has to be a hard stop, and mid-20s is it for *almost* everyone.