I think the bitcoin will fall because of RANSOMWARE,it is impossible/Difficult to track who did this and in futur Bitcoins will be considered as a motivation mean for such act
I do not want to say that you are wrong, i mean it could happen that this will be start of more and more ciber attacks. But i do not think that it is untracable. There is always a way, and not to speak that if it becomes a problem in the future, it would be dealth one way or another. Bitcoin has made a long way to this point, and it will be hard to die after so long.
impact of ransomware is able to make business systems that use bitcoin will work harder to develop security in maintaining user accounts, when viewed from business side it's interesting because the antivirus product or the latest system will continue to be developed, I see a conspiracy on this even though not completely certainly.