Why shout into the wind?
My experiments in online interactions have only proven that null responses indicate the effort was of no use. It reminds me of that old adage about why children behave badly: because any attention is better than none.
It's built-in to us: as children demanding attention is a survival instinct; since we can't see to our own needs, we must coerce others to do so. As adults we do not have this problem, but we still have the instinct to demand attention. It must be fulfilled in some way, even though we are not conscious of our motivation.
So we go online and express our opinions, thoughts, feelings, dreams ... whatever. We say nice things, we say nasty things, we say poignant things, we say outrageous things. Then we wait for the reactions whether they are good or bad.
Why? Because we need to engage; to be part of some community, any community, in order to fulfil our human trait of the sociable being. Negative encounters discourage us initially, but the lack of positive reinforcement inevitably causes us to reengage as we now need the good experience we didn't have even more. A positive engagement likewise sends us back again as we seek that dopamine jolt that made us feel good, and each dose increases our need for a larger dose to get the same effect next time.
Yes, the Internet is a drug: the reward of it is neither necessary to our lives nor real in its return.