Here's why we say "salt to taste" for all amounts of salt.
Salt is a health issue long before it's a taste issue. There are people with high blood pressure, salt sensitivity, kidney disease, liver disease, and a whole host of other ills who must avoid salt for medical reasons.
We are fortunate not to have these illnesses, nor are we trained professionals who can advise others who have them.
"Salt to taste" is our shorthand for "Salt more or less of none for your health and then, if salt is good for you, salt to taste."