If there is too much regulation, the results are often contradictory and so byzantine that they will be ignored. If there is too little, preventable catastrophes like this will happen. Every regulatory and standards agency in the world wrestles with these problems. Adherence to regulation and standards alone will not keep catastrophe from happening.
Though I have little knowledge of British law, I would hazard a guess that the building owners, the consulting engineers, the construction firm and anyone else involved in this affair are probably at risk of a ruinous day in civil court, and maybe even worse than that. Even if there were regulations that permitted this sort of practice, it is no excuse.
As a reminder, the unfortunately named Torch Skyscraper in Dubai burned in February of 2015, and it was made worse by similar exterior cladding. It was only the most recent reminder of the problems with this sort of material. The threat of fire from these practices should have been known to people in the business for years.
Just as you aren’t necessarily safe driving at the speed limit, so too it is with standards and regulations. There are always going to be things that no standard will cover. It does not absolve anyone of responsibility. The question that needs to be asked is whether installing a bureaucracy would have kept this sort of thing from happening in the first place, not whether this or that policy is evil.