That's not a problem with the pedestrians -- it's a problem with the road planning.
If there's enough foot traffic that you'll get a constant stream for long periods, the planners should have put in a light if they want cars to pass.
If it's a one-off random surge for a few minutes, the cars have to wait. There is no right of way for cars to push through an in-use pedestrian crossing.
In the 5-thick crowd example, it's pretty clear that the status quo was actually maximizing the rate at which people (whether in cars or on foot) crossed the intersection. Cars use too much space to compete with that flow rate.