I don't know this particular company, but many reputable event organizers around the world (not just running, but other sports, art, science, tech trade show, etc) are doing the same thing now, and no, it's not shabby business practice. It's an emergency situation.
The legal contract of your registration (which you click 'ok') is likely to already say you don't deserve reimbursement. You don't pay to do buy the race itself as service, but to buy the planning and reservation. The security guy that already earmark his calendar to work that day will still have to be paid. The municipality already budgeted the road closure fee and spent it on whole bunch of other things that can't be undone without breaking many other contracts.
If you want security, buy insurance that cover pandemics. Or live in a country where the regulation mandated reimbursement, or maybe where races are free (but they come at other costs: high tax, or high sign-up fee). Uncertainty cost money. Somebody has to pay for it.