Well FO4 is a Role playing game so saying that the purpose of game isn't this or that is hardly correct since the purpose/goal changes from one player to another, from one play through to another
and from one faction to another. The SS goal is primarily to find his/her son and the one who murdered their spouse, but the other factions have their own goals/ambitions.
The MM goal is to re-build the Minutemen and to take back the CW "one piece at a time".
So this how I would like the MM quest line to be but I also think that freedom of choice (role playing) should be implemented since I respect that others do not want it like this.
So don't call it stupid just because you disagree/are of different opinion.
So I disagree that it is stupid to have the MM take Quincy back since it makes allot of sense from a story point of view since Quincy is a very important locations in the MM history. I can agree with
that Q is too bog to be a settlement in it's entirety just like Jamaica Plain is but that is solved by using only a part of the locations as a settlement zone. Then, ok clearing the entire map of hostile
is too much/ambitious. Especially down town might/should be hard However the MM should at least be able take back not only Quincy but they should also be able to capture other strategic
locations such as radio towers, Gunners Plaza (since GP is television broadcasting building) and some of military installations/forts in the CW (after you have finished the MQ) Along with
the establishment of farms close to these locations.
The purpose with this is to re-establish the MM as well as a first step to make them a regular army.
Obviously not all at locations once but "one piece at a time" as Preston says. Like with the castle you need a certain number of settlements (and I think a certain amount of settlers)
and you'll be able to take a minor location (like a radio tower) but to take Q and GP you/MM would need to be very strong with many settlements and settlers to recruit soldiers from.
So GP and Q should be the two last locations on the re-build MM quest line.
Sure Q and GP are two very good places to farm XP/weapons/ammo/apparel/equipment but personally I am not fond of re-clearing the same locations over and over
again for eternity. If you don't want to clear/capture these locations then just don't do the quests.