That looks like a great schedule, particularly if you note that Mass is paying for it.
In general the job of this train is to "beat the bus" by piercing I-95/I-91 rush hours directly (in the morning) and connecting with after-work NEC trains that beat NYC traffic. The Weekday schedule does this masterfully.
1) They totally nail the "supercommuter" market on weekdays--the same thing that powers so much of recent NEC successes (and is how the Downeaster works). It delivers a workable solution for living in sponsor state (MA, in this case) and working/consulting in "The Big City" (New Haven, Stamford, or NYC).
2) "Weekend Getaway"
from NYC to the countryside works too, provided you leave after work on Friday and return either Sunday afternoon or first thing Monday morning.
3) "Weekend Getaway"
to NYC works for students, taking a Friday train or an 9:15 Saturday, and staying at least one night visiting friends and relatives in NYC. Train market + Student/Rural == couch-surfing market, not "day of sightseeing"
I can't see any public policy reason why MA would or should want to encourage weekend daytrips to NYC. None. MA wants you to do your weekend day trips in-state, thank you very much. If New York would like to MA people to day visit, let them sponsor their own train.
Neither would it be worth chasing a weekend day trip *to* MA. We want you to stay overnight (it also is not clear what a day trip to Greenfield would look like frankly. Sure, Railfans would love to shout an echo into the Hoosac Tunnel--a big market on RR.net, a small market in Real Life).
Meanwhile, recall that SPG is also a bus hub, and mostly this train needs to worth with the trips the bus is already doing, and by being/connecting trains that beat rush hour.