The point that you are manifestly missing is the general one of the right of the State to censor the public record. Of course it is open to the legal system to decide what enters the public record in the first place,. There is a reasonable case for juvenile offenses being kept secret (which they are in the UK and many other regimes), in which case they never reach the public record in the first place, but remember the adage "not only has justice got to be done, it has to be seen to be done".
Go to a local library in the UK, look up the files of local newspapers (whilst we still have those) and you will find court cases going back through history. Of course nobody is much interested in minor convictions (unless you make yourself a public figure), but in any event, if it is information that is part of the public record, rather than what might reasonably be considered private information, then tough, live with it.
None of this is any reason to allow the publication of new personal data about a convicted individual. For instance, the publication of , addresses, telephone numbers, new photographs and so on where there is no public interest. Once a person re-enters private life then there are issues of privacy and secutiry that apply, and certainly those who actively seek to persecute individuals beyond what the legal system deems to be a fit punishment need, themselves, to be answerable to due process. But that is a world away from censoring the public record which is exactly what this is about.
Jennifer Granick has it about right on her EFF blog.
"At stake is the integrity of history itself. If all publications have to abide by the censorship laws of any and every jurisdiction just because they are accessible over the global internet, then we will not be able to believe what we read, whether about Falun Gong (censored by China), the Thai king (censored under lèse majesté) or German murders. Wikipedia appears ready to fight for write once, read anywhere history, and EFF will be watching this fight closely. "