Well, the bigger problem would be ensuring that the criminals used known broken encryption. The only advantage is that many of these attacks are copy-cat, so if you released the source code for a broken ransomware implementation, it will probably get used more or less verbatim… as has been shown in the past. (https://threatpost.com/bitcrypt-ransomware-deploying-weak-cr..., https://www.utkusen.com/blog/destroying-the-encryption-of-hi...)

Anyone who actually knows what they are doing, and are prepared to break the law, would just use AES. All of those law-abiding institutions would be forced to use a weak encryption scheme.

Sure, it might help stop script kiddies, but it won't help to stop professionals, and professionals are the ones that you have to worry about, since they end up hosing 45,000+ installations in a day.