Oliver Wendell Holmes the younger famously said in his book on the common law, "The life of the law has not been logic; it has been experience." Much the same can be said about language.
During the just-past graduation season, a colleague lamented that we no longer say that a student was graduated from a university. To say in active voice that the student graduated implies that the student performed the action. Rather, the university conferred a degree upon the student.
Whatever the logic of that point, was graduated, a construction common during the first half of the 20th century, was steadily fading out during the second half and is now almost completely gone. The active graduated has replaced it in common usage, and that is just how it is.
At the same time, graduated as a transitive form — "he graduated high school" — has remained a colloquial usage. Fastidious writers avoid it, but it will bear watching.
Much of the language is idiomatic: the usual way that words are used or arranged, or a construction that has a meaning different from the literal sense of the words. Idiomatic comes form the Greek idiomatikos, "peculiar," ultimately from idios, "one’s own." Idiosyncratic comes from the same root.
One of my professors in graduate school grew irritated with a student in his Anglo-Saxon class who kept developing rationales for the assignment of gender to inanimate objects. In the several languages that do this, the professor insisted, gender is always arbitrary — idiomatic. Establishing a rationale for assignment of gender would only be persuasive if it could be predictable, not worked up after the fact.
Recognizing the prevalence of idiom is particularly important in English, a magpie language that has both Teutonic and Romance components. (We retain alumnus, alumni, alumna and alumnae, and the plural of nouveau riche is nouveaux riches. That’s the way we do things here, thank you very much.) In such a language, reasoning by analogy will not get you very far. Think of those tiresome questions posed in little articles or poems on English, such as "If the plural of mouse is mice, why isn’t the plural of house hice?"
Margaret Fuller, intoxicated by Transcendentalism, said, "I accept the universe," and Thomas Carlyle, told of the remark, supposedly said, "Gad, she’d better." Accepting English, as it is and as it is developing, is also the sensible choice.