What would Dotcom gain from having a weak crypto system. Plausible deniabilty will work up to a point, but the government can still subpoena his encrypted data,

What would Dotcom gain from having a weak crypto system. Plausible deniabilty will work up to a point, but the government can still subpoena his encrypted data, crack it themselves, then require Dotcom to comply. And if Dotcom actually acted (or even accessed) the data, then he would through plausible deniabilty out of the window by demonstrating that he does have access to the data, in which case the entire exersise in creating the cryptosystem is pointless.