Today they might have better trust for Wikipedia-- and I know I use it as a source of truth for a lot of things-- but back in my day teachers were of the opinion that it couldn't be trusted. This was for like middle and high school, not college or university, so we would cite encyclopedias and that sort of thing, since we weren't reading cutting edge papers back then (maybe today kids read them, who knows).
Edit: Also, I think the GP comment was proven correct by all of the replies claiming that Wikipedia was never controversial because it was very clear to everyone my age when Wikipedia was created/founded that teachers didn't trust the internet nor Wikipedia at the time.