Source: Civil Litigation (Feb. 2010). pp. 29 Bottom - 30 Top.
In Canada, lawyers are officially both barristers and solicitors but, as a practical matter, most will work primarily as one or the other. So-licitors, whose work rarely takes them into court, need to understand the law of procedure as a backdrop to their area of specialization much as they do the other basic areas of law in which they do not specialize, but barristers who practice in the area of civil litigation come to know
court procedures and rules through and through. In jurisdictions with a divided bar, such as England and Wales or Australia, the judges are traditionally drawn from the ranks of the practising barristers. They, too, have a keen interest in the law of procedure and a considerable knowledge of the rules and precedents. This may help to explain why the rules of court in many jurisdictions are cast as regulations rather than as statutes. [Bold mine] They are a finely tuned set of interrelated rights and obligations between the parties to the dispute and, sometimes, other affected persons, and the collateral effect of changes to the rules, which may be obscure to persons who do not regularly work in a courtroom setting, is likely to be obvious to those who do.
I understand the distinction between solicitors and barristers under jurisdictions with split legal professions, but still don't clinch how this explains the bolded sentence?