// We would still trade and we did so perfectly well before being in the EEC ... //
I don't get this argument. The world was a very different place 40 years ago; never mind the fact that the premise is somewhat twisted. The motivation for joining the EEC in the first place was that we were not trading "perfectly well" at all, and that the UK's economy was lagging behind its competitors, in Europe and elsewhere. If the best argument for Brexit is that it takes us back to a time pre-EEC then you seriously need a better argument.
Meanwhile, AH's post is also rubbish. Firstly, it misrepresents the Remainer argument. We'd clearly still trade in a No Deal scenario, but we would do so under very unfavourable circumstances, which all countries if they can seek to avoid by arranging trade deals. If that happens then trade continues but becomes far more expensive, both to UK businesses and to UK customers. Nobody sensible can want this to happen. Yes, it hurts the EU too, but the "reality is" very much not what you claim. Around half our trade is with the EU; on the other hand, about 10% of their trade is with us. Maybe in absolute terms they stand to lose more than us from trade disruptions, but proportionately the UK takes a far greater hit, and in this case that's what matters. We can't try to bully the EU, or use No Deal as a sanction or threat. At best it's a Samson act, but that's still not exactly something we can plausibly carry out.
AH's post, therefore, is full of the same sort of twisted logic that's got us into this mess in the first place.