I'm not sure what your point is? The comment I was replying to said "we know this is always true" I said, actually, economists aren't really sure about that issue. If your concern is that economists aren't good at making certain predictions, then guess what, we agree. Economists are also acutely aware of this fact and most of the ones involved in actual economic research are careful not to overstate the implications of their models.

Regardless, I simply have to laugh at your comment. The "finance bro says economists are all morons who would be traders if they actually knew anything" trope is pretty great!