There's a belief among some gamers that the cracking of a console somehow, magically, enables people to cheat in online games. And driven by that belief and a hate for cheaters, they go after the wrong target.
The belief is mostly correct however, although it is true that the targets are indeed wrong. People doing the initial grunt work of cracking a console are not the same people as the ones developing cheats.
The cheating on PSN, up until now at least, has been entirely through exploits of binary saved game data (which can be transferred to and from the console freely). There was widespread hacking long before any jailbreak.
Don't get me wrong, jailbreaking certainly opens up other avenues, but Sony (and developers) had been doing a very poor job of anti-cheat for a long time. With the jailbreak, they simply found a scapegoat that they hoped would take the heat off of them.
