You're not comparing apples to apples. The goal of money laundering laws is to make it harder to profit from crimes, achieved by the means of e.g. violating financial privacy.
The goal of copyright laws is not to "prevent dissemination of information" but to encourage better intellectual works by granting their creators temporary control of them; this is achieved by the means of restricting some kinds of copying.
Both intents are noble; to characterize the goal of copyright law as "preventing the dissemination of information" is the wrong comparison.