You lot just don't get this, do you?
I am not criticising the captain, who had no choice and did the right thing.
If an aircraft encounters conditions beyond its capabilities or those of its crew, then obviously it must divert.
But, in my opinion, if a capable aircraft cannot land due to being despatched with a crew who are less capable, then company despatching that aircraft are going to have a hard time convincing a small claims court that they acted reasonably.
One has paid an airline to provide an airline flight and that implies the crew will be up to doing the job, for low visibility is hardly unknown in winter.