I'm still not quite sure what about this Russia story gets my blood pressure high but I have a few candidates:
For one it is a throuroughly xenophobic rightwing framing of events.
It goes full Red scare. Remember that the first Russia Stole the election paper from the spooks copied the part about RT from an older report. This report detailed Russia's dastardly plan to undermine democracy by giving fracking oponents a platform. And now Russian trolls promote Standing Rock protests? Convenient.
This story is brought to bear as an argument for arbitrary political censorship by private companies. Remember propornot?