During peak times this is what busiest of the bus stops at our downtown campus looks like, if not worse, actually its generally worse by the time the next bus gets there. The downtown campus also has a 4 story parking garage and multiple surface lots, so its not even totally bus dependent. On top of that the classes that are centered around this area are business, engineering, CJ plus a hand full of others, and we only have 25,000 people that go here. Where the real problem comes in is that the bus on this route comes every 5-7 minutes, so you cant even say that frequency is the issue. So if during peak times a well organized system of buses will struggle with just a portion of a medium-large sized university, how is it supposed to work for a city of millions?
For reference with the amount of people that are here it will fill a standard sized bus, including the aisles, shoulder-to-shoulder and leave people waiting for the next bus.