It also practically prevents an extension of existing Middleborough/Lakeville service to Buzzards Bay, which would serve Wareham, a community of similar economic status of Taunton, New Bedford and Fall River at a much less capital cost per projected passenger.
This raised my eyebrows, as it isn't an angle I've thought of before for Cape Rail. As it turns out, this is somewhat true:
https://en.wikipedia.org/wiki/List_of_Massachusetts_locations_by_per_capita_income
Rank | Municipality | Type | County | Per capita income | Median household income | Median family income | Population | Number of Households |
235 | Wareham | Town | Plymouth | $29,740 | $59,186 | $74,960 | 22,086 | 9,125 |
267 | Taunton | City | Bristol | $26,446 | $51,637 | $66,969 | 55,953 | 21,657 |
291 | Fall River | City | Bristol | $21,257 | $33,211 | $42,962 | 88,811 | 38,258 |
293 | New Bedford | City | Bristol | $21,056 | $35,999 | $44,607 | 94,927 | 39,068 |
That said, it's worth noting that Fall River and New Bedford both fall in the bottom decile when ranked by per capita income, and Taunton just barely falls into the second decile; Wareham is significantly higher on that measure. Fall River and New Bedford are joined by many familiar names in that decile: Revere, Worcester, Everett, Lowell, Lynn, Fitchburg, Brockton, Chelsea, Easton, and Lawrence. It's also noteworthy that Wareham has anywhere from 40% to as little as 23% the population of any one of Taunton, Fall River, or New Bedford (and less than 10% of the three of them combined).
I think it's reasonable to mythbust the notion that Cape Rail is meant to serve places like Hyannisport, and I of course think it's a crying shame that the current build for SCR is going to forestall Cape Cod Commuter Rail for the foreseeable future. But SCR would serve a lot more people. How many more?
175K on Cape (including Yarmouth and Dennis), plus another 23K in Wareham, yields a total of 198K at the most generous. Fall River, New Bedford, and Taunton alone trounce that at 238K; if we apply the same "one town over" logic that brought in Yarmouth and Dennis, we add another 91K (33K of which comes from Dartmouth), at which point SCR's "population served" count tops out at 329K, leaving Cape Rail's 198K in the dust.
(And for what it's worth -- the shorter extension to Buzzard's Bay drops the Cape Rail numbers down to 41K. Taunton alone beats that, and at a third of the distance, too.)
So, I think there's good nuance to add here with respect to Wareham, but I do think it's not comparable with the gateway cities, as you note, that will be served by SCR.