Yeah....I say yes for a few reasons.
1 - It will prevent the accumulation of garbage on the tracks. Platforms are easier and safer to clean rather than going down onto tracks and run the risk of getting electrocuted.
2 - It will prevent accidents such as people/inventory falling, and careless people risking their lives. We're not always going to have subway heroes. And, if you remember that ill-fated lady who jumped down to her death for a mere bag(I still think that was her fault), things like that the doors can prevent.
3 - The doors can also prevent the wind tunnel that a train causes as it enters the station. Wind tunnels can knock people off their feet.
4 - You really don't have to worry with the length of trains. IRT is fine, and so is BMT/IND with 10 car trains. The only real worry, now that I think about it, are 75 footers, but this can easily be remedied by placing more platform doors at different intervals. Overshooting seems to be the only major factor, but lines that have ATO and CBTC like the (L) would be the first choice for platform door testing.
5 - Ray brought up a very interesting point. There are parts of the five...I mean four boroughs that do have high levels of crime and therefore it would not be very wise to place glass platform doors at stations....why not plexiglass? In any case, MTA would lean towards plexiglass anyway, as a cost-cutting measure(you know how much they love that).
6 - If you're now hearing about vandalism on a transit system, then you must not ride transit often, or at all. Still, there are easy ways of removing graffiti from glass and stainless steel, a reason they were implemented in the first place. The MTA started putting plastic protectant on the glass of the trains, like a screen protector to a phone, and so far it has helped for as long as I've seen them.
7 - "In case of emergency, pull handle. Then push doors open." Works on the NJT Multilevels and all of the subway fleet. In fact, the Multilevels have a feature where you can remove the rubber around a window and easily just push it out. And i'm pretty sure that in case of an emergency, there would be no reason for the subway entrances/exits to be closed off. It's much more dangerous to walk in the tunnel.
8 - Everything mechanical fails at some point. Dead motors, service dump, spontaneous BIE, etc. As long as mankind makes machinery, there will always be one or two flaws. We can never expect that something will work on its first day, or over a long period of time.
That's just my two cents.
BStyles