I guess for me it comes down to recognizing that this is not about the whole group. Big groups generally consist of many smaller groups. Like communities within cities or high schools where there are jocks, preps, emos etc. They all go to the same school, they all have some interaction and they come together for specific classes at specific times.
I have riding friends. We are separate within a bigger social environment because we ride motorbikes. Therefore we do things that other friends don't. We do however come together at different similar interest times like lunches or coffee room chat.
Educational get togethers and social events with our poly friends are open to everyone but not everyone goes because they are not interested. The concept of a social network of people who will explore sex together is the same although it is more closed. That does not mean that when they are not having sex they still won't participate in the social gatherings and educational meetings.
Although they are engaging in a different activity I don't see it as being a deeper level. Do I feel like people are worried they won't be accepted because they don't go to poly family events? Nope....I bet they don't either. Is that another level? Sure it is.
Every group of people with similar interests will also contain smaller groups of people with "other" similar interests. Like the people who play Role playing games at our parties. They sometimes break off and do their own thing. We all spend time together at other times.
Will the group splinter because of smaller groups forming? Maybe...but group dynamics are hardly static.
Do I think group sex play will be the defining attribute of my local poly community? Nope..and if it does than live and let live, it won't be my community any more.
The question is is this a matter of wanting to be included in everything...or wanting to be included with the "cool kids".
Playing the Game of Life with Monopoly rules.
Monogamy might just be in my genes
Poly Events All Over