Parliament got rid of government fire inspections in favor of self-policing some years ago. They also refused to pass a law--such as exists in the US and most European countries--to disallow this type of cladding for buildings of a certain height. They could have, but decided against it.

which didn't test the panels under actual conditions.

This is a test of actual conditions. The sample on the far right is rock wool with metal panels and second from left is rock wool with a continuous exterior. The other two are cheaper core materials and I think we can guess which one was on Grenfell:

the company was able to market it in Britain (though not elsewhere).

The facade, installed last year at Grenfell Tower, in panels known as cladding and sold as Reynobond PE, consisted of two sheets of aluminum that sandwich a combustible core of polyethylene. It was produced by the American manufacturing giant Alcoa, which was renamed Arconic after a reorganization last year.

Arconic has marketed the flammable facades in Britain for years, even as it has adjusted its pitch elsewhere. In other European countries, Arconic’s sales materials explicitly instructed that “as soon as the building is higher than the firefighters’ ladders, it has to be conceived with an incombustible material.” An Arconic website for British customers said only that such use “depends on local building codes.”

For years, members of Parliament had written letters requesting new restrictions on cladding, especially as the same flammable facades were blamed for fires in Britain, France, the United Arab Emirates, Australia and elsewhere. Yet British authorities resisted new rules. A top building regulator explained to a coroner in 2013 that requiring only noncombustible exteriors in residential towers “limits your choice of materials quite significantly.”

...

****No aluminum cladding made with pure polyethylene — the type used at Grenfell Tower — has ever passed the test,**** experts in the United States say. The aluminum sandwiching always failed in the heat of a fire, exposing the flammable filling. And the air gap between the cladding and the insulation could act as a chimney, intensifying the fire and sucking flames up the side of a building. Attempts to install nonflammable barriers at vertical and horizontal intervals were ineffective in practice.

https://www.nytimes.com/2017/06/24/world/europe/grenfell-tower-london-fire.html?_r=0

Check out the entire article for the full explanation. This falls squarely on the government's back.

most notably in the UAE but also in Chechnya, France, Beijing, and (I seem to disremember) Brazil. In all cases, a fire spread rapidly up the exterior of buildings, spreading inward to flats through heat shattered windows.

I agree that the bulk of the blame belongs to the government. It can also be spread to anyone involved in the process of choosing the type of cladding that went onto that building.

No wonder!

Something tells me that's going to change, and very soon.

Follow the money

And in those rare failures (nobody could have anticipated this!) God will clean up the mess.

I offer these free marketeers cholla cactus they can fuck themselves with.