According to my dad, tule fog used to be much worse when he was a kid. He always tells me of the time when there was a fog for nearly a month in December one year.
People are pretty much used to the fog now. Yes, there are times when extreme caution is required. I sometimes have to pull over to the side and wait for a while because I fear pile-ups. There have been 100 car pile ups in the past years because of tule fogs.
On the other hand, my uncle is a farmer and he claims that his produce turns out better when there is a lot of fog that year. So there might be benefits to the fog but the disadvantages are still more.