Sure, but that influence has not exactly been positive. That's the catch I think. It's much easier to exert negative influence than positive influence.
It’s not that simple. Tribalism is easy and most considered a net negative. Tribalism is easy to sell because it’s ingrained in humans. That’s what 4chan does, pick the lowest hanging fruit.
It’s a tool, it can be used for good or evil. I’ll leave the subjective analysis to others but I think tools are rare just good or bad.