The thing is, I suspect that most plyg families are simply not interesting or controversial or full of enough drama to be interesting to read about.
That was my observation a long time ago is that most of the thing about poly is decidedly domestic. Cooking, chores, child care, and etc. are up front and center. The secular world focuses on the sex but while that is a part of the life the majority of daily life isn't all that exciting.
I guess that's part of why when I hear from ostensibly poly people it's the ones who don't have much drama going on who I tend to more quickly accept as grounded.