For transparencies sake, I have attended Terra Nova fairly regularly (say 2-3 times a month?) for a few years. That said:

It seems to me that the difference you are speaking of has more to do with different denominations and their communities approach or degree or beliefs. Catholocism (in general, there are always exceptions) has a stereotype of being exactly as you described, a traditional or socially based thing where family and community ties tend to trump the messages being preached. You will see a lot of this in other denominations as well, but you will also see some of what you described at TN where people take it fairly serious.

This is not anything unique to TN though. Loads of other churches (even in the Capital District) are going to have similar church structures or preachers with similar messages. The way I always look at it is that churches are going to fall into a grid of two axes, one of the degree to which they believe XYZ and one where you see the results (typically either 'good' or 'crazy') of said beliefs. By that I mean are the people using their beliefs to care for the homeless or are they Westboro Baptist apprentices out picketing abortion clinics. For an outsider, that second one is what matters, but for a member/participant both will matter. For someone like you, being around people who take things more serious would be uncomfortable for precisely the reason you describe. For others who are more serious, they would prefer to be in a community at a similar level, so in turn they might not stick long attending your mass.

All of that said, I'm not sure I'd use the term cultish for TN. (But of course as someone part of the group I would say that :) ) To me that has some really heavy connotations, typically of tight control of the membership by the leader(s). IMO that is not the case at TN. The church is essentially identical to thousands of other churches out there. The distinction/draw for me and others is as frickonature suggested, that A. the community is younger than most churches and B. they "seem like they live in modern times".

As a tl/dr I guess I will go with: sincerity of beliefs does not necessarily equate to "cultish" tendencies.