Dictionaries supply very generic definitions of terms. That's why specialists use subject specific dictionaries - medical dictionaries, law dictionaries, science dictionaries, etc.

On the other hand, if one's motive is to confuse rather than to elucidate, it makes a lot of sense to use as broad a definition as possible in the hopes that some prospective subject of indoctrination might conflate the various definitions.

"Fanatic isolationalists who call themselves scientists,"
You incorrectly apply the term "isolationist" here. Most scientists recognize there is a relationship between science and society and many scientists, philosophers, and historians try to understand and clarify that relationship. The isolationism that you refer to is one where someone from outside of science is attempting to confuse the subject matter by changing the definition of science so that it might include a support for their particular cult.