The term 'Public' is one of those meaningless terms, but it is not without harmful implications.

There is no public, only a specific group of individuals.

Thus, when it is claimed that something is in the public interest, what that means is that it is in the interest of a certain group of individuals and probably not so much in the interest of a different group. 

The word's existence only serves to confuse and manipulate people, much like the phrase the 'general welfare' which would more accurately be the 'general's welfare, if the general was understood to mean those elites who rule over the rest of us.