Look at how easy it is:
"Hey guys, there was an impact event on Jupiter, similar to the one that happened in 2009, might be another com—" "NIBIRU SLINGS ASTEROIDS INTO JUPITER!"
"Bad drains and composition of the rock and soil in Gautemala causes sinkho—" "NIBIRU IS PULLING AT OUR CRUST! THESE THINGS AREN'T NATURAL!!"
It takes no effort and research in order to grab a video or series of photos and title it "Nibiru does this and that, we're all doomed." Bunny hopping onto the most recent event and stating that the cause is Nibiru is the done thing - you know, what with all the other stuff they say having been debunked.
By the time you get round to explaining how sinkholes and comets, while spectacular, are normal, they're onto the next event - who cares about Nibiru causing sinkholes when it causes sunspots?