My understanding is that pay for parking (aside from large garages) is generally about space availability rather than making money. Public street parking in Boston is fairly cheap per unit time and my understanding is that the maximum time limits are meant to allow new people to come in and take the spot to do whatever business they need to do in the area. Otherwise people would just squat on spots all day and the businesses would be starved for customers.
Not disagreeing with all the other shenanigans you listed for Ma though.
I've heard that cities also charge for parking because of an interesting social factor: many people will drive in circles for half an hour looking for a free spot rather than pay for parking in a private lot. Everyone driving around in circles creates more traffic. So the city charges for curbside parking, in order to make the cost more comparable to parking in a private lot, with the hope that it will lower the psychological switching cost from "finding a curbside spot" to "giving up and paying for a garage spot".
My annoyance with metered parking in the area isn't so much the cost which, as you say, isn't very expensive. Rather it's that a lot of 2-hour metered parking has been extended from ending at 6pm to ending at 8pm. What that means is that, if you come in for dinner and an evening event, your meter will probably expire before 8pm.
(There is a hack with the online parking app to "feed the meter" although you can potentially get ticketed for that.)
Exactly. If parking time limits weren't enforced, commuters would just park there, hurting local businesses. (I say this having been on both sides of the equation.)
I agree with your assessment, but not entirely. If it weren't at all about making money you could just stand up a kiosk that dispenses parking tickets and not charge money for them. The ticket-to-park method of parking enforcement doesn't require the payment element to enforce parking laws.
Not disagreeing with all the other shenanigans you listed for Ma though.