I think MTA should also consider putting a barrier on the edge of the platform. So that we won't get dozens of people being pushed off to the rails.
As much as it's a feel-good measure, there is no conceivable way to justify the incredible expense of platform doors for such a small number of instances.
And the dirty secret is most of those are suicides. If they can't kill themselves on a train, they'll just go to the nearest bridge.