As this question does not seem to be eliciting many responses I will add my own view. My perspective comes from reading many books written by Puritans, in fact this has been my main diet as a Christian. Unfortunately my view is limited by my knowledge of the history of the early colonies in America.
From my own perspective the Puritans as a group of more or less independent Calvinists, settling among the early colonies of America, were nothing more than Christians getting caught up in a part of the world seeking opportunity and wealth in a new frontier. Among the population of the general crowd, filled with ambition and greed over the many new opportunities, the Puritans would have been seen as intolerant for sure. Also it would have been no surprise that some Puritans were truly judgmental and even racists, as we would still find people in churches today with that disposition. On the other hand, among the colonies there would have been many brave and regular 'good folk' who have taken a chance at a better life and would not have been caught up with the greed of the industries, but would have been simply wanted a quite life and kinship among townsmen, etc. Here there were probably be less of a contrast with the Puritans among them, for this simple life of hard work and honest living is somewhat Puritanical. These sorts of people would have many things in common with the Puritans and the churches in those communities would have probably been less criticized.
Aside from the typical stage that a movie might present the old west and the little church within in it, when reading the actual writings of the Puritans what I find is a big emphasis of love and charity which opposes the concept of casting an intolerant monoculture. Among the Puritans there was also efforts to bring salvation to the native Americans. I think this is where the picture has its truth on both sides. Some in the name of religion tried to eliminate native culture and stole the children to be 'educated' etc. Possibly even sexually molesting some of them. However, I think this trend was not so much the Puritans but other denominations, especially Catholic as we find similar things today. Yet considering the great racist and vile attitudes of the colonies against the natives, some of that prejudice and racism and rigid monoculture values of the British, that plagued many parts of the world, would have also infected even loving and holy British men to some degree.
I find this specifically true of the accounts that Jonathan Edwards has in his diary of attempts to be a missionary to the natives. You can tell he loved them but there was some monoculture and rigidity in his words. I perceive them as trace elements reflecting the wicked arrogant white-man society in which he lived, not his own sentiments. In fact when trying to understand how to show liberal compassion and love, I like to read Jonathan Edwards.
To answer the question, I think the new frontier for many Europeans was a place to force their rigid and mono-cultural ideals upon weaker races and this would have stained, to a degree, even the good hearted puritans that sought a simple life to honor God. Among these groups some Europeans especially those who were physically attracted to other races would have probably spent their liberal days in local saloons and would have cursed the Puritans just as party goers curse holy people today. Sinners often feel judged by holy people even when they are not judged. Drunkards and fornicators would have been more 'easy going' and less ridged, yet also the most ridged when facing races where no attraction or mutual financial benefits existed, such as with the natives. So really we have many aspects to the answer that are probably not that different than how things are today. Are we rigid and trying to force a monoculture today? In some ways people would say we are but in many ways, especially in our love, we are truly not. Many people would think Jesus was rigid and monocultural in that he required every nation to repent of their idols, but that does not make the insult true.