I think you are correct on the last point, but I for one, would genuinely welcome a cogent argument from a Leaver who is able to articulate the benefits, both current and expected (based on an evidential footing).
I accept this thread can be a bit of a pile on for strident Brexiteers, but previous iterations of it were too. The difference now is that the effects of Brexit are real, not expected or theoretical.
It is against that backdrop that people who support it, and are able to articulate their enduring reasons for that, should feel confident in asserting their reasons for that.
The fact the none are is most telling.