It's not a political hobby horse jayne.
It's simply highlighting a matter of which people may not be aware. As you say, large numbers of people are wearing flip-flops at the moment (ghastly things IMO, totally naff and appropriate only for use around a swimming pool, but no matter). It's also true that many people are driving in them. As with a number of things (using a mobile phone, fiddling with a radio, drinking to excess, eating their breakfast, doing their makeup, slurping coffee) lots of drivers do not consider the dangers posed to others by their inappropriate behaviour when driving. This is just a reminder.