> Intention matter a lot in US law.

They hacked a competition company. The intention was implicit when there is economic gain to be had.

> People are not charged with hacking when their unsecured box is taken over by a botnet and does bad stuff.

Because it is a lose for that people. If the botnet left money in their pockets the situation would be totally different as there will be an incentive for them to let the botnet hack them.

> The intention was implicit when there is economic gain to be had.

Not how it works. Intent requires at least that you were deliberately doing the criminal act (sometimes also that you knew it was criminal, or at least that you had some reason to believe that it was wrong).