Most of our ideas and ideals about "family" start with the notion of "biological kinship." Typically our ideal includes a father and a mother and a child or children.
This "traditional" type of family has many strengths. Although we now widely accept "blended" families, studies have shown that the #1 cause of child poverty is parental separation and/or divorce. Also, step-parents are much more likely to abuse children who are not biologically related to them than they will their own children. In fact, studies show that children from traditional families are much more likely to succeed in a number of key areas than those who are being raised by a single parent or who are a part of a blended family.
This is why I am concerned about re-definitions of family -- not because I want to force couples to stay in loveless marriages or because I want to impose my standards on others or because I think people shouldn't have a second shot at happiness. Simply put, I believe we have made a great number of changes (no-fault divorce, for example) in a relatively short period of time without considering the effect of those changes on children in particular and society in general. And, when the results have not turned out the way we hoped, we have turned a blind eye and looked for other scapegoats -- "if the public schools were doing a better job" or "if the government offered more assistance," etc.
I'm not saying any of this to judge single parents or blended families. They need our understanding and support. What I am saying is that we would be wise to slow down and study the changes we already have made and see if they are actually working to our benefit. If they are, okay; but if they're not, then what steps can we take to correct them?
The alternative is to continue down the road of redefining family and then hope for the best. Is that really the best we can do?