Others have mentioned fears of skidding in slippery conditions if RDMS interferes with steering .
I have mine set to' delayed' and find it does not often twitch the steering even on narrow lanes , and when it does its just a minor tactile 'hint'.
At first I wondered why it sometimes does twitch while most of the time, in apparently similar circumstances , it does not.
Two reasons I think. On very narrow roads I am often under 30kph/18mph so the system is not yet active . And at faster speeds I may be using the accelerator ,brakes and steering often enough it detects active driver input, which overides activation.
The system is probably less likely to detect road margins, lane markings and the like in snow.So wouldnt activate. It certainly wouldnt stop you driving into a snow filled roadside ditch.
It might activate in ice, mud, loose gravel ,wet leaves etc. But you could argue that the best defence for this is to drive much slower in these conditions . If it gives you a fright ,or worse, in these circumstances you may have been close to the safe limit of traction anyway.