Why does Melbourne Airport get crippled by fog?

[_BlackHawk_]

I remember at least 5 years ago they were meant to be upgrading the airport to allow aircraft to arrive and depart in fog. I presume it has ILS and ground base radar to track aircraft taxing, so why did fog again close down the airport this morning? Is it the aircraft that are unable to do it or the pilots? Although I can't imagine that a commercial captain wouldn't be trained to fly in low visibility or by instruments. Or is it just that everyone is being extra cautious, in which case why would you bother having the ability to allow aircraft to land in low visibility. Just wondering.

[davecana]

I was in a Cathay Pacific plane that landed there at 06:30 this morning. It was fairly foggy, at a guess looking out the window, around 1000' vis.