Sure, you need to take externalities into account. One can imagine an audiophile who would rather spend $100K on a sound system that sustains 3 jobs at a niche sound-system-design business, instead of angel-investing that money in a growth company that would eventually create 300 jobs. But what if the audiophile's daughter is then inspired to build another growth company when she grows up, because she was intrigued by how much her dad would geek out about the electronics in her sound system? Nothing is clear, it's incredibly hard to quantify probabilities about any of these things. As long as the audiophile isn't neglecting responsibilities or breaking windows to obtain his sound system... that is, as long as negative externalities are not a foregone conclusion... we should let him enjoy his passion.
Certainly, there are valid moral arguments to allow, even encourage, this state of affairs. I was just pointing out that the economical argument that was offered is a broken window fallacy. Refuting an argument in favor of X is not an argument against X.
