I think the point is that the "frat boy" ideas come most often to people who have a romantic idea of business, but lack the will to actually make it happen. So

I think the point is that the "frat boy" ideas come most often to people who have a romantic idea of business, but lack the will to actually make it happen. So if they don't really have the will to do it, then yes, one should discourage them from doing it. For their own good. People with will will ignore the advice anyway. (Will will will!) That said, the desire to build a book exchange is like a nerd disease.