The heuristic/algorithm is Facebook's creation, so they (including possibly you?) are to blame either way. I think GP is pointing out the fact that there being no clear rules or accountability on what gets surfaced on our timelines allows much more subtle and virtually undetectable ways to suppress information than previously. It all can be easily hidden behind the magic/complexity of the all-knowing "algorithm". I do find this to be a novel and very concerning vulnerability in our collective sense-making.