"What is really going on is the judge correctly understands the difference between positive rights, which don't exist except by fiat, and negative rights, which are what the Bill of Rights guarantees."
Yes, the judgement is correct if one myopically focuses (as seems to be the way in the US) on what logical conclusion is reached by extrapolating The Constitution.
An no, many rights (and prohibitions - incitement was mentioned) exist only by 'fiat' - that being the collected decisions of the branches of government.
But those fiat decisions exist to remedy the flaws involved in taking an autistic view of an 18th century document and trying to create 21st century law from it.
The difference is this case is the amount of centralisation inherent in 21st century forms of 'speech', where private 'speakers' hold the power that, it was envisioned in the 18th century, only a government could ever hope to hold.
Good law is created by only ever making such fiats incrementally, so as to give time and space for challenge along the way. There are laws about political spending on TV 'speech', rules about balance in journalism and more of the like in the UK, where only 'fit and proper' persons (realistically excluding only fraudsters and terrorists) may hold a broadcasting license. The judiciary is independent in order to allow it the leeway to make these kind of incremental changes, and this is what society would clearly have expected in this case. All the more so in tech circles, where we understand, eg, the existence of filter bubbles and the meaning of Google's annual censorship stats.
The judge cannot have been unaware of this expectation, but has declined to codify such a change. Maybe the claimants sought too big a jump, but the effect now is that he has knowingly given search engines (and the government, since they can also mandate filters for search terms) complete freedom to censor search, without explanation and based on criteria invisible (and probably unknown) to users.
All in order to stand up for the principle (which seems sadly absent in cases involving the rights of 'natural' persons) that the constitution must be interpreted inflexibly.