Curmudgeon and me.
Quick easy fixes that show you've "done something" are popular with many politicians, and the nanny state meddlers of the SNP are no exception. The real problem with drink-driving is that some drinkers will drink whatever they want and then climb into their car and drive, without ever giving a second thought to the limit. The driver who carefully drinks within the limit is not the problem, but he or she will be hit by a reduced limit, not the lunatics who are the real danger on our roads.
At the time the Scots adopted the lower limit, the UK government said it had no plans to reduce the drink-driving limit in England and Wales as it said this would have no impact on "high risk offenders". Despite that sensible approach, I can't help wondering whether, with the ongoing cuts in police numbers, it may at some point become tempting to cut the limit in the rest of the UK. Okay, the result is that you spoil the pleasure of careful drivers, and you close some pubs in the process - but you can claim you're "doing something" and being tough on the causes of crime. And not only that, it's a nice, cheap option - much cheaper than tackling the hardened offenders.