The problem is also the way the US does these things. The amount of hostility and the way they treat people.
As for this case I am pretty sure their intent was to break the law, they just did not expect the consequences. They did try to get J-1 so they knew they need a visa for their visit and a waiver is not enough. They went without a visa anyways, probably hoping to talk their way through the immigration, feigning ignorance.
Any country without a jumbled mess of a legal system?
www.wsj.com/articles/SB10001424052748704471504574438900830760842
I reckon you have a point: So many people come to US with the intent of lying to the border agent, getting a tourist visa and working. Border law isn't shoplifting or traffic law.
Well, ignorantia SHOULD be "excusat" in some cases.
That idea of "Ignorantia juris non excusat" ("you're not excused for not knowing the law") is one of the worst and most undefensable aspects of the legal system, especially since modern law has become so vague and all-catching.
http://www.wsj.com/articles/SB100014240527487044715045744389...
It should be checked on a case by case basis, and actual ignorantia should be taken into account and count as a reason for a lesser penalty.