These generally do, only because no one else will ever pay a ransom if they don't. That is not to say the victim is going to be left alone afterward. But as Baltimore just found out, it can be many times more expensive to fix if you haven't been doing your IT homework than it is simply to pay the ransom.
Diligent, thorough backups and keeping the patch levels up to date and this doesn't happen. Laziness and lack of professionalism and it does. Choose.
Daily backup saved the area I worked at from similar trouble, though it seemed to be a simple gather the address book and send itself out again type of attack. One wrong click.
That is the description of 99.9999% of IT shops (of which another 99.9999% is dominated by H1B visa holders).
Just another example of government ineptitude. Nobody will be fired for these screw-ups. Nobody backed up the data? Nobody patched the software? Nobody was working to keep hackers out of the systems? We really should be privatizing almost all government services.