This may be a little naive but my hunch is the Bretons have got it more right than wrong.
France operates an ultra progressive tax regime. It is possible to earn more gross and yet your net income goes down. This 'threshold' is around Euro80k. So there is a disincentive to work - too hard. Naturally round here some restaurants only open 2 months a year to avoid the wealth trap; Shops charge premium prices because they are happy to work on low volumes, high margins. Lower sales (but with higher margins) also set lower expectations for the taxman. Easier to avoid Inc tax.
Then try to find non French products in the supermarkets, very tricky. It is an unofficial (cultural) trade barrier. Harder to police and more efficient. And of course those not working their socks off the two main summer months have the whole of august off any case.
Wonder where they are on the IMF happiness index, probably not very high. Pissed off they haven't won world cup for a while and they don't get July off as well.