It might be quite rare, but it will still happen and there lies the problem.
The majority of golfers are older and more at risk as has already been said.
All the people saying it will be ok, have probably not had any real experience of the virus.
Im in my 30’s and pretty healthy yet it gave me a fair old fright.
Im 3 weeks from showing symptoms and still not quite 100%.
If people don't follow the rules re social distancing on the course. It's only gonna be in their groupings. I highly doubt they will be hugging strangers or walking down wrong fairways just to get close to people.
A few weeks ago, people who were saying we shouldn't golf used non essential travel as the only real defence. Which was fair enough, but now that rule has been changed, there really isn't a reason to stop it. Now people are saying that if we start golf then people will revolt and play football and rugby etc. Well Other activities have been going on for five weeks now and that hasn't happened. I'm pretty sure people can tell the difference between contact and non contact events. There comes a point where people needed to be trusted to do the right thing.
I can't see any proof that golf is any more dangerous than a walk, cycle or run. Now if the government decide to ban all exercise due to contact being possible then that's fair enough.
I have been massively effected by the outbreak btw, but that doesn't mean the world should or feasibly can be expected to live in solitude for ever.