Who's fault it is?

My school is classified as "under-performing". This classification is based on the high stake standardized test by our state. Since our school opened almost five years ago, the students have taken this exam. After the scores get averaged we come out with a low number, thus the classification.
Indeed there is some true to that label, but who can take the blame?
The principal? the teachers? the students that are lazy and lack motivations? the parents? Maybe different combination for each student? It is possible that all groups involved are performing well but they lack trust and are not able to synchronize meaningful learning? Seriously, how do you measure learning?
I belong to the teacher group and I constantly interact with the other four groups. The best foundation for our interaction is true trust. I believe they can do their jobs and I want the to believe that I can do my job. I turst that they have the best intentions to reach our goals and I want them to believe that I have the best intentions to reach our goal.
There is one group that I don't trust completely, that is the parents. I feel that parent from our demographics are not prepare to support the academic needs of their children.
In our school students receive everything, from pencils, notebooks, colors and even some get free backpacks. Since many of our parents work in agriculture related jobs, they lack the financial means to provide for their kids, therefore we provide. I see no problems with that. But for some parents this act has paralyzed their sense of responsibilities. This has transferred to homework and being aware of what their kids should be learning.
What do you tell parents whose kids has lost their homework folder that was provided to communicate with parents? "you need to buy another folder for your kid". this is what I feel like telling some of my parents, but would I be too imposing?
there is so much to this issue that I don't have enough time to continue. I shall ponder further on this on the future.