people calling it a sensible strategy or solid 'risk assessment' really surprises me.

You are to a large degree in charge of your risk. Proper, fullblown, 100% fabcricated accussations seems exceedingly rare. I've never seen any stats and the anecdotes I hear are often 3rd or 4rd degree.

Be a decent human being and you are probably still more likely to get struck by lightning or die in a car crash.

Meanwhile, the cost of walling yourself off from 50% of your colleagues (or as a manager, to avoid 50% of the workforce) seems like a very high cost to your career.