Why is en primeur subject to different rules?

Last week, a new Consumer Rights Directive became law across the EU. Apart from limiting the supplement retailers can charge for paying with a credit card and the amount they can make from making unhappy customers wait on premium phone lines while desperately waiting for someone to answer their questions, the directive has doubled the statutory period during which consumers may return goods bought in-store or online from seven to 14 days. In other words, If I buy five dozen bottles of Champagne from Majestic, I can legally return two unopened six-packs a week or so later and expect to get a full refund.

The same applies to investments. There is a similar 14-day 'cooling off' period that allows me to change my mind about the wisdom of putting my kids' inheritance into a new fund focusing on selling wine in Saudi Arabia.

So far, so clear. But according to a news piece on decanter.com, the Wine & Spirit Trade Association has, after a 10-year campaign, won an exemption for en primeur sales. Apparently, my order for 10 cases of 2013 Chateau Coûte-Trop-Cher is 'exempt from the right of cancellation'. In other words, en primeur wines are treated totally differently to wine bought in bottle, or any other kind of investment.

Now, I entirely understand that it would be crazy to allow buyers to ask for a refund once the wine lands on their doorstep possibly two years after the purchase. After all, since the 2009 vintage, merchants would regularly have been handing back more money than the post-delivery wine was actually 'worth'. And some people might actually have wondered about the wisdom of buying en primeur in the first place - and considered the alternative appeal of that Saudi investment fund.

But why, I'd like to know, shouldn't en primeur simply be subject to the same 14-day rule as everything else? Apparently, the wine establishment prefers to set its own rules, with Corney & Barrow honorably giving customers a month's cooling off period, Berry Bros allowing just seven days and others presumably applying the letter of the (new) law and refusing any cancellation at all.

Could somebody please enlighten me on what makes en primeur - an odd concept in any case - deserving of such special dispensation?