It's not. I defend the HC always, do you? It's not his decision to not attend BYU that irks, it's his frankly stupid reasoning. If you aren't going to break the principles of the HC anyway, the heightened penalty is irrelevant. The ONLY time it becomes an issue is if you plan or believe that breaking it is a possibility. Hence the don't want the consequences statement.
Being baptized increases the penalty for sin, as does receiving the priesthood, going to the temple, getting married, or becoming a bishop or an apostle for that matter. Going to BYU is a blessing and with it comes greater opportunities and consequences. That is the reality and part of most everything in life.
If you don't want the consequences of living a higher law (not referring to BYU per se here), you also forfeit the blessings attached to thT higher law.
Good luck to that dumb kid, not dumb for not choosing BYU, but for not understanding such a basic truth.