Salt has a noticeably salty flavor, and people can easily detect its presence and take precautions; MSG does not taste salty, and its presence can easily be ignored.
但值得注意的是，食鹽吃得出鹹味，大家會對其中含有的鈉，心生警惕，而味精的鹹味是吃不出來的，容易忽略。