the first time it rains it’ll be back to normal
Yes, but the new cyclists who go back to their cars in the rain will now appreciate what it’s like, say, having a motorist pass you at 40mph six inches off your bars, and will drive more considerately as a result. Even if they don’t ride every day those new riders are still a good thing for the rest of us.
FWIW I’ve not seen any new riders on my commute this week, but then I hardly ever see anyone riding to work on a bike round here anyway. Last week I was in Essex and all the motorists were being suspiciously tolerant and careful, I got slightly freaked out by it…