I don't know how a trust works in the UK, I have some experience with them in the US. (I'm a retired accountant).
I think this may be a smart move on their part. In the US a Trust is an entirely separate entity from the beneficiaries of the trust. That means it is very difficult to hold the trust financially responible for damages incurred by the beneficiaries (elders). In the event of a lawsuit the KHT's defense will be "they didn't do what we told them to do," And "We only handle funds for the building."
This would shield the WTBS from judgements. They may have the effect of stopping lawsuits, because the lawyers can't get at the Society's money and the elders typically don't have any. Situations like that leave lawyers explaining to their clients that, while they may have a good case, there's nothing to get if they win.
If I was an elder and knew all this I'd quit on the spot, I have no desire to be hung out to dry.