"Actually changing things" may involve "criticizing congress" but I expect it to be rather more complicated. I think that all of the players in this case should have exercised discretion. The fact that so many people (including the citizens of America) allowed this situation to occur is the tragedy.
I think that the Aaron Swartz tragedy is not an example of an acute failure in America's legal system that we can blame on any specific element: the prosecutor, the congress that passed the law, or the court system that allowed this legal case to proceed as long as it did. I think the legal case is an example of a complete breakdown of America's legal system. In America we have 3 general wings of government that all have a hand in the legal system:
Legislative (e.g. Congress) that writes the laws.
Executive (e.g. prosecutor) that prosecutes potential violations of the laws
Judicial (e.g. the court and judge) that decides whether potential violations of the law are actual violations
I think we can justifiably criticize Ortiz and congress and the judge and Aaron and The American People for their roles in this mess, and I expect that all of them will need to improve before the situation does.
All of the players had opportunities to exercise good judgement and they all failed when presented these opportunities.