Sorry, but as a US citizen I have to say the US really isn't that important.
Yes there would be a price dip, but no, the vision would not die.
And no, congress won't make it illegal because of this anyway - that's an absurd proposition.
ransomware predates bitcoin.
What congress might do is create laws requiring adequate backup of medical databases and fine hospitals that don't do it.
I didn't say congress would make it illegal because of what has taken place so far, but things could get worse. Also, the terrorist angle could come into play if it is connected to an ISIS attack for example.
Ransomware predates bitcoin but it could never take place on this scale without it. If this hospital payed by any other means it would be easier to track.
And saying congress won't do something because it is an "absurd proposition" is pretty much the definition of what the gov't often does. Most americans thought it was an absurd proposition before 9/11 that the gov't would torture prisoners, and not only did they do it, but now the leading republican candidate is pro torture.
And to say the US isn't important in global finance is naive. If they can get enough countries to comply to shut down the economy of Iran they can make it difficult enough to exchange fiat->crypto that wide spread adoption never occurs.