These are the dangers of a relatively young and highly volatile market -- fake-outs and manipulation attempts through unsubstantiated rumour and fearmongering are nothing new for its older brother Forex and even there they are greatly successful from time to time:
https://www.bloomberg.com/news/features/2018-06-25/brexit-big-short-how-pollsters-helped-hedge-funds-beat-the-crash
And now that Bitcoin is being taken seriously by old school trading profiteers... Well, let's just say I would never bet on this being the last such incident.
That is a very good point. There is a famous quote from the movie Wall Street that comes to mind...
But why do it???
"Because it's wreck-able! All right. That's why!"
If the big guys can get away with it, they will do it.