I think a lot of people don't understand statistics, which may make it hard for doctors to choose how to communicate things, even if they do have important knowledge that could be helpful.

I once asked a doctor how long a relative might have to stay in intensive care:

A: Oh, I couldn't possibly say.

Q: Do you think he might be home in 3 or 4 days?

A: Oh, no, not that soon.

Q: So it might even be as long at 3 weeks?

A: I highly doubt it would be that long.

Q: So a reasonable estimate might be 1-2 weeks?

A: Oh, I couldn't possibly say.

I started the conversation having no idea whatsoever how long it would be, but I ended up with a good feel for a time estimate along with error bars.