Have you looked up biographies of all the judges (High Court, Court of Appeal, Supreme Court, European Court of Human Rights) and ascertained that they were all childless? It seems improbable that none of the judges have children. I can tell you for certain that the President of the Supreme Court, Lady Hale, has a daughter, and one other Justice of the Supreme Court who was involved in this case, Lord Wilson, has a son and a daughter.
I’m also not sure what you mean by “activist”. I think I’m correct in saying that you are from the USA. The judiciary is perhaps quite different in the UK, as well as in Europe more generally (at least with regard to the European Court of Human Rights, which is a body of the Council of Europe). British judges are appointed completely independently of the government. There is no process such as you have in the USA of executive appointments confirmed by the legislature. Our judges have no political biases, explicit or implicit; they are appointed purely based on their expertise in the law. Indeed, the chief responsibility of a British judge is to interpret and apply the will of Parliament.
Lady Hale is a woman of the most extraordinary intellect. She ruled in a Supreme Court case in which some friends of mine were involved and when I read her judgement I was just astonished by the clarity of her reasoning. She is probably a genius, having finished top of her year in her law degree at Cambridge and top of her year in her bar exams. She became a member of the Law Commission at the age of 39, the youngest person ever to serve on the commission, and she was a professor (what Americans would call a “full professor”) by the age of 41. As for Lord Kerr (who by the way was a Queen’s Counsel by the age of 35), he was the Lord Chief Justice of Northern Ireland, a role in which one would imagine that absolute objectivity would be essential.
I think you may be projecting some of your prejudices about the judiciary and reaching some unfair conclusions.