Judge decides that he is a lawmaker now. This unfortunately happens quite a lot. It erodes trust in the judicial system
But you are right —- it is not. I would object to someone saying the government can’t move faster and not break things, however.
I am not a lawyer, but if I recall correctly there are three types of law : statute (what parliament legislates), common law (that which has built up over the centuries as "just the way we expect the law to work" and precedent ("this was unclear at one point but courts down the years have been convinced that what it means is x"). Appeals are usually on the basis that the court has misunderstood or misapplied the law and the outcome of these appeals form the precedents for future cases.
This case is an appeal; if a judge in an appeal case interprets the law in a particular way, that sets a precedent that should be followed by judges in lower courts, if the circumstances are similar. That's not "making law"; laws here are written to be interpreted by judges, because that's how it works.