"Bond" is not one thing that's always the same. There are different types of them and different degrees of them. I'd guess there are also different qualities of them. When people talk about children and the word, "bond", they often refer to only one kind of bond, which is the mother-child bond and/or father/child bond that happens (or is supposed to happen when things are right) in the first few years of a child's life and that is unique (and of whatever quality it is/isn't) to that one relationship between one parent and one child). In the case of a baby/young child who has been separated from his/her birth mother/parents that bond can be formed between the adult(s) acting as parent(s).
So, people need to sort out all the different types of bonds there in all kinds of different relationships, recognize that when things are right in the parent/child relationship in those first few years that unique and solid relationship is not just the foundation for the structure (that will be the bond that grows and shifts as the child and parent grow together as individuals and as "a team"). That foundation will also (when things are right between that parent and child) "grow into being a big part of the 'structure', itself."
I think there are all kinds of less-than-whole bonds between any parent and a child, some "more less-than-whole" than others"; but when things are right, and whole, between a child and a parent that unique and powerful bond is "It" when it comes to, say, the mother/child bond.
People who have that with their own parent/parents know what it is. People who become a parent and have that with their child know what it is. People who have that relationship long enough to see the child and the relationship grow also see how that "structure" changes but how that "foundation" never weakens and only grows more solid with team (again, when things are as they should be).
People who have not shared that kind of powerful and whole bond as a parent often don't know the difference between all the different types of bonds/relationships and that particular one. This isn't saying other types of bonds aren't good or important. Life and "socialization" aren't supposed to be just about the parent/child bond. It's just saying that when things are right and whole with the parent/child bond it is powerful and unique to the relationship; and all other relationships go in the "Other" category.