Na, the comparison with food and tea is over-simplifying the matter.
In the Western society we already have a junior-senior structure - but most people just do not seem to be aware of it. Perhaps because in daily life we no longer have it in a formal structure, but it is nevertheless there.
By practicing sempai - kohai structure (to me it is part of keiko) in the dojo one becomes conscious of it. And this may have a positive effect in the way we help and support one another.
I remember several training sessions by Tamura sensei were he explained sempai - kohai as a way to support each other. There was no emphasis on hierarchy as such. This can also be found in his books.
The problems that I have seen in a number of Aikido dojo were a result of NOT understanding sempai-kohai relation, and with that came often also a not understanding of the real relationship between teacher and student. Instead of a sempai-kohai structure they had an ordinary pecking order.
As far as the university shenanigans - don't you have them in the US as well? They do happen in the Netherlands, UK and France and they are usually between senior students and newcomers. And it has been like that for a long time.
It may or may not have had an effect on their teachings in the beginning, I am not aware of that.
I would not discount the effect of pre-war militarism either - I think it is important that everyone who practices Japanese Budo should educate themselves about the history and become also aware of the dark side of Budo.
At the same time I feel that in that period all over the world a lot of things that were in itself innocent and even good were stolen from us and misused.
There is "a" junior-senior" structure, but it is markedly different than the one in Japan.
In the same vein - there are shenanigans in US universities, but that doesn't mean that all shenanigans are the same.
Tamura's view is a little idealized, IMO - there is a definite heirarchy in many circumstances - and a whole lot of pecking order in Japan. Actually the record in Japan (and in Aikido, too) among Japanese is not that great. What do we get from importing that?
And if it already exists in western culture, then why do we have to impose another system that does the same thing?