The meaning of a word doesn't care what your opinion is. Enough people believe a potato salad is a salad that it has to be contained within one of the definitions for salad.

I'm absolutely horrified by the way kids use "literally", but that definition has achieved critical mass and must be included in the dictionary.

The insistence on a single definition is where the silliness of the original article comes into play. There are obviously multiple definitions of salad; you don't have to accept all of them.