A web site banned as a source for facts from schools the world over now bans a web site as a a source of its banned facts.
At least, that was my experience.
I'd argue that its strength is exactly being a secondary source, instead of just alledging facts someone has already taken the time to value multiple sources. Additionally the talk page often adds extra depth.
Instead of blindly hyping against Wikipedia, it should be taught to use it well (and not depend on it too much).
https://en.wikipedia.org/wiki/Primary_source
> In the study of history as an academic discipline, a Primary Source (also called an original source or evidence) is an artifact, document, diary, manuscript, autobiography, recording, or any other source of information that was created at the time under study. It serves as an original source of information about the topic. Similar definitions can be used in library science, and other areas of scholarship, although different fields have somewhat different definitions. In journalism, a primary source can be a person with direct knowledge of a situation, or a document written by such a person.
Many, many things in a classroom will be primary sources.
Students used the internet a lot, and Encarta (lol), and were constantly getting grief from teachers for doing so.
Be my guest, but good luck getting anyone to believe it.
edit: I'll just note, additionally, that you stated "nothing in a classroom is a primary source". Even if it were true that yours was an unprecedented aberration, that general statement remains untrue.
A primary source is one that "creates" the information of history, e.g. a letter, journal entry, official announcement, or original research. A secondary source (nominally) synthesizes and summarizes primary sources into a coherent narrative.