i grew up in boston (actually newton & then brookline) from 1970-1989 and i'm 3rd generation after goalie-mom and my (late) goalie-grandma both being born & bred in boston (n.b. i was not born in boston but moved there in '70 at the age of 11, hence my "growing-up" in boston).
my 2 "sense" on bostonians being polite is that they are not. simply put, most (not all, but most) bostonians are rude and self-centered and when people ask me what boston is like, i 'splain it this way....
beautiful scenery (beaches, moutnains & lakes) any day of the year (yes, even in winter and the last 2 weeks of august
)
a history buff's paradise
a sports nut's nirvanna
one of the last bastions of bigotry in america (i grew up during the "bus crisis" which will always be a black eye for the city)
political & religious corruption run amok
worst drivers in the lower 48 where the the "state bird" is not always the black-capped chickadee
like i said, this is most but not all bostonians and my apologies for sounding harsh (and i'll take my 2 minutes in the box) but it's painful to honestly criticize the place you call home (even tho i live in sf, boston will always be home)