How is America?

When you live for some period of time abroad, you wonder how to depict the more and less subtle differences. Sometimes you do not even recognize them, sometimes you do not know how to conceptualize them.
Here is one, I (still) cannot make sense of.

To my experience, it seems that stairs are usually a representative part of a building, and for this reason it may seem legitimized to put them on a crucial spot in the building.
Even more, security, safety and emergency concerns may impose additional restrictions on how to design a building and its stairs. no wonder, that soccer stadiums tend to have many many gates, in order to fill/empty the structure quickly (quess what would happen in panic, when you seem not to be able to move out quickly? Don't tread on me...). And so it comes that you see not only audience, but many gaps due to gates and stairways which cut across the rows of seats.

But let's look at a more common type of stairs, in buildings of every day use. We might expect huge stairs in huge buildings, for huge crowds and to make a huge impression on the visitor. this may be valid for Gaston/Healy Hall on the Georgetown Campus (likewise for European palaces, but similarly - scale adjusted - also for single households).
But - where are the stairs in the Walsh School Building? Where are the stairs in the ICC building or in the Lauinger library? They are not representative, not impressive, but closed up, away from the main hall/entrance room/atrium. As if the stairs are not a part of the building, but something to hide (and indeed, their walls are sometimes not even painted). And those stairs are small, maybe not even 1.5m (or 6 yards?) wide...
WHY????
Given that those few elevators are slow, old and small, they do not tend to provide enough capacity for the loads of students, faculty and others to get through the structure.
Is there any good reason for this? Cutting costs? Space constraints? Static challenges?? Or just different conceptions of how (thought of) modern buildings should look like?

If you have a powerful explanation, let me know.