I mean, to compare apples to apples, this is the platform area. Take your examples of Moynihan, GCT or the Oculus - your train doesn't arrive in the grand waiting hall and concourse. At NYP and GCT you still board at
a rather dank and cramped underground platform, and likewise the platform at the WTC is also much more utilitarian than the headhouse above. The arches are a comparatively "grand" interstitial space between platform and headhouse, and more exposed by nature of being ground level and not underground.
I also think its a mistake to think of this in the same way as Moynihan and other recently built or renovated transportation hubs - this wasn't a passenger experience project, its the literal foundation of the skyscraper above it. Its infrastructure - a pretty foundation that we get to walk under, but thats what it is. The concourse is filled with problems, but its not affiliated with the tower developers.
Besides... Its also useful to note that Amtrak, Boston & the MBTA didn't pay for these arches and platform improvements. The developer did, including the significant and yet to open Bus Terminal expansion. That alone is a major expansion of the facility as a whole, and its basically a gift to the city and MBTA thats worth a hundred million dollars. Thats not to say its perfect, because as this thread will attest its not, but it is good.
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