What motivation could we have? Most British people you talk to on the internet are distinctly unhappy about Brexit and, if anything, are motivated to talk up the single market
~37% of the electorate voted for it, six years ago. If you think it has become more popular in the intervening time then it may be that you're in the echo chamber.
I don't know about the economist but there's certain stipulations that went into the foundation of the single currency that favored Germany heavily, and Germany behaved the whole time like it didn't happen.
Most of the european resentment comes from that fact. Most southern european countries were taken for a ride during those negotiations, and have paid (and continue to) a steep price.
I was a strong believer in the common currency but after reading about it for a while I'm not convinced it was a good idea anymore - if you're anyone except Germany or France.
Paul Krugman wrote at length about why that was a mistake, and he was 100% right about it.
Note that it is a "single currency", not a "common currency". In the same way that the "single market" is different from the prior "common market".
So if the UK had joined at the inception, it would have started as a common currency, but when the UK decided not to join, it reverted to the preferred form of some of the other members, namely the "single currency".
I imagine that the rules would have been different with a common currency, possibly with the national currencies not replaced, and still operating in tightly tracked bands; but I guess the UK fate there was written when it dropped out of the ERM as part of "Black Wednesday", caused by it entry peg being overvalued.
So a common currency may well have allowed for more north vs south flexibility...
France hasn't really benefited much. Italy has been the talking point for a long time and rightly so for the amount of debt plus the chronic political instability, but France is very much on a similar decline path.
Edit: cheap Russian gas + high productivity + political stability + undervalued currency (the Deutsche mark would have been way stronger than the euro) is what fueled German dominance in Europe. Italy/France/Spain/Greece/Portugal all struggled with varying degrees with low productivity, political instability (apart from France) and a currency that was too strong for their macro-economic fundamentals.
>President François Mitterrand argued for the single currency because he hoped to bolster French influence in an EU that would otherwise fall under the sway of a unified Germany