It's worth noting that Wikipedia is not special in this regard — those same departments probably also consider it bad style to cite Britannica (and, if they don't, they should).

Encyclopaedias are meant to be starting points for research, not the ultimate destination. Editors, both of Wikipedia and otherwise, are not expected to be subject matter experts, which is why the guidance on Wikipedia is that you're not even supposed to use primary sources as reference, but rather secondary sources[0].

0. https://en.wikipedia.org/wiki/Wikipedia:No_original_research...

But what happens instead (in people’s published journal papers! not to mention news articles, etc.) is authors lazily crib material from Wikipedia and then either cite nothing or randomly pick works from among Wikipedia’s sources to cite without ever looking at them.

If you are writing a paper you should cite where you got the information. If the only place you looked was Wikipedia, that’s not great research practice but you should still cite Wikipedia. Honesty is an even more important part of scholarship than diligence.