Pardon the social science observations of a Baptist who is supposedly a specialist in organizational behavior (with a genuine M.A. in the field too!). My intent is NOT to speak to the actual culture of the PCA (pretty presumptuous for a Baptist), merely to make some quick analytical observations about typical organizational behavior as it applies to the question being asked.
It is my understanding that the history of the PCA was constituted through a flight from more liberal denominations over issues such as inerrancy and Christology. Both in the original context of the early 70s and with the additions in the early 80s, the churches were mainly part of more liberal groups and wanted to keep their conservative identity. In this sense the ethos was shaped by a combination of the somewhat latitudinarian praxis in the parent bodies coupled with conservative theological convictions. Since then, the emphasis has been placed on expansion into suburban settings.
Judging by the originally more "relaxed" practice of the parent denominations and by the effort to penetrate the suburban American culture, it is not surprising that PCA congregations would be somewhat more open to "innovations" than some of the smaller and more insular Reformed denominations. Whether with the church growth movement of the 80s or the Willowcreek-ization of the evangelical church since then, "Shine Jesus Shine" approaches have become the currency of the land.
In my own group, which fairly recently broke away from a mainline denomination over issues of inspiration of the Bible and homosexuality, our experience may prove analogical, or at least instructive. As treasurer of the organization, I can testify to the fact that we work very hard NOT to be our ecclesiastical parent. However, some of the ethos, the practices, and elements of the corporate culture (or corporate DNA if you will) continued with us into the new body. Outside of the issues which led to our separation, we tend to be blind to other negative elements of the mainline group we emerged from.
Since the PCA grew out of disgruntled conservatives from more liberal groups and has been committed to an aggressive program of church expansion, it should not be surprising that so much of the "Shine Jesus Shine" approach has crept into the Presbyterian fold.
So, what implications can we draw from this mini-history in terms of the original question?
1. Groups involved in ecclesiastical splits (whether local congregations or larger groups) typically carry a bit of the pugilistic flavor of separtistic divisiveness with them. Such a negative ethos continues for a long time. That is why so many congregations that angrily split give rise to other congregations with problems of divisiveness.
2. On the other hand, the smaller Reformed groups tended to keep their identity, often shaped by ethnic factors, into the present. They were often more homogeneous and maintained their confessional identity as central to their corporate ethos. Groups such as this may be expected to objectify the "other" as an outsider to the tradition. Strangers would be suspect as possible threats to the tradition. Insofar as insiders behave like outsiders, they would likely be viewed as traitors or prodigals.
3. What do you expect? They are all Presbyterians, after all! Like Baptists, they are famous for their cantankerous inability to get along. It has something to do with deleterious impact of the fall on our volition and emotions, I think.
4. In addition to #3 above, the PCA might suffer from two negatives: the left over spirit of division they began with AND the unexamined openness to modern innovations "inherited" from their original denominations. Both of these realities can create problems in a congregation. The smaller Reformed bodies, being definitionally more insular, will be bedeviled by the irritating "know it all" spirit of criticism common to both Reformed expressions of Christianity and sociologically smaller bodies.
So, they both have problems! Welcome to the real world!
At this point, however, they ALL sound better than where I have come from!
Better an intramural debate over details of the RPW or being EP than livng with apostates who ordain homosexuals and believe all roads lead to heaven!