Nice thing about NYC is that housing is a right based on the Callahan v. Carey ruling. Every person that asks for temporary shelter is supposed to have access to it. It's not perfect, doesn't have the funding or capacity to deal with the bussed in migrants, but it's better than most cities/states. And it does more to address the issue directly than viewing benches as a crutch for the problem.

But re the engineer question, I think Moynihan probably had a lot of engineers. And safety, security, egress, congestion, etc were considered in the design which is why they put seating around the perimeter and not the center of the hall.