I hear you. I imagine that young man regretted using the word "whim," and in further posts it seemed that he had indeed done more research about the CG that his original post implied. It took me several hours to distance myself to be able to counsel him from my training rather than my emotions.
I have hesitated to throw this out there, but IMHO, the nomination process (or some other arduous process) would greatly minimize people applying to the USCGA impulsively. The USCGA process "feels" more like a regular college process (with a physical fitness test thrown in for "fun"), so applicants perhaps don't realize the difference between going to a good engineering school and signing up for military service with educational and employment privileges and guarantees. At minimum, it would seem the interview should be mandatory rather than optional.
I know the current nomination system is fraught with frustrations and imperfections, but I know for our DD, it was a hugely beneficial experience. Even though her process did not lead to an appointment with the Navy, her research led her to discover the Coast Guard, which in so many ways is a wonderful fit. If being waitlisted does not yield an appointment for the class of 2020, she is definitely applying again next year.