academist
n.n. a person who is very focused on academic rules and theories, often to the point of ignoring practical needs. You use this to describe someone who is too strict about following the rules of a subject.
n. a person who adheres strictly to academic conventions, theories, or formal rules, often at the expense of practical application. Frequently used in a critical sense to describe someone who is overly pedantic or detached from real-world concerns.
The project failed because the academist ignored the practical needs of the workers.
The committee was dominated by an academist who insisted on following every textbook rule, even when the situation required a more flexible approach.
While the academist argued for a purely theoretical framework, the practical team pushed for a model that could be implemented within the current budget and timeline.
From French académiste, from académie (“academy”).