It's literally self defeating - you could just as easily say that he has no right to privacy for the contents of the harddrive because the contents of his harddrive is "jUsT aN iNtEgEr" and no integers are secret.
Some patterns of bits are clearly and rightfully illegal.
If you take any reference to a concrete phenomenon - the extreme difficulty of policing private data storage and communications - and pigeonhole it into a simplistic caricature, then it's no wonder you see that everywhere?
If most child pornography enthusiasts are caught due to having their computer fixed at Best Buy, have you actually criminalized viewing child pornography, or would it be more appropriate to say that you've criminalized patronizing Best Buy? As stated, that's obviously hyperbolic as bona fide CP enthusiasts are an extreme minority. But we can imagine tripping up innocent people with the letter of the law (eg botnets, teen sexting, unregistered pornography), as well as similar dynamics around much more common "patterns of bits" like say pirated Hollywood movies.
I would say that this is true, the police should be free to try to brute-force his password or crack the encryption used via some other method that does not involve forcing said person to act (such as disclosing his password). Although in said world the police would not have any reason to attempt to decrypt said data as it would be legal.
I'd always argue the latter; as I can kill someone with a rock, but making rocks illegal seems unreasonable.
contents of his harddrive is "jUsT aN iNtEgEr" and no integers are secret.
Right, but the pattern is secret right? If someone happens to derive it by brute-force then, well, secret's out.