Re: That argument goes both ways you know.
Rephrase it as "hardly a decisive outcome to make a major constitutional change". That argument doesn't go both ways. Changes as huge as leaving - or joining - the EU are, as you may have observed, spectacularly expensive and complicated. There should be a higher bar to making such a change than a simple majority. Otherwise we could end up leaving/joining/leaving/joining every time the opinion polls fluctuate above or below 50%. You need some hysteresis in your control loop.