Move to relevant forum if needed...
Aren't they more likely to be judgmental towards cyclists? Or those intending to take up cycling? Especially their loved ones? Don't they tell others it's unsafe to ride a bike? Don't they base their claim on reading news about cyclist deaths? Won't they agree among themselves that cycling to work will make you at risk of losing your job because you'll be too tired to do it properly?
As someone who took up cycling almost four years ago, with no intention of ever learning to drive, and fully aware of all the potential risks (thus always plans the route before cycling), I tell those non-cyclists to go f themselves. Lecturing people about how dangerous it is etc etc, when the benefits massively outweigh the risks - what's the point? If you really want to tell the whole nation that cycling is dangerous, you'd pay someone to knock me or some other cyclist over. But you wouldn't because you'd be in jail.