Quickseller often invokes this sort of rationale "it doesn't make economic sense to do __" in discussions.  What's fun is to look through his posts and see how the __ is often in contradiction to itself across time.  That is, he's happy to reason at one moment that some behaviour makes economic sense and then later that it doesn't.  What I'm highlighting here is that whether or not something makes economic sense is actually one of the hardest things to find agreement upon: thus the varying behaviour of people (both within and across).  Quickseller might argue, it doesn't make economic sense to scam, yet we find scammers, so it's not really valid to suggest that because QS says something doesn't make economic sense means that we won't find anyone doing it.

Here's the kicker, even if there was universal agreement about what does and doesn't make economic sense (which clearly there isn't), we have the problem on top of this that people are not rational.  Anyone who actually studies economics knows that the idea that people are perfectly rational agents who always act in their own best interests isn't true at all.  People act emotionally, irrationally, etc all the time, often against their best interests (economic or otherwise).

I don't know that this will help QS (logic and argumentation isn't really his strong suit), but it might help others here to avoid taking the bait when QS offers it.  The argument that 'X does/doesn't make economic sense' isn't intersting or valid if you're trying to support a proposition that people will or will not do X.  The official name of this logical fallacy is non-sequitur (doesn't follow).  For fun reading see: https://en.wikipedia.org/wiki/Non_sequitur_(logic)

Cheers!