I'm very sad about it but have come to the conclusion that I agree with Melvyn Bragg that the National Trust is a bullying and arrogant charity, and not the force for good I had always thought it was.
In addition to all the comments on this thread about how it treats volunteers and visitors to its properties, there is this awful incident concerning a farm the NT bought in the Lake District, using its financial muscle to outbid the local community www.theguardian.com/environment/2016/sep/03/national-trust-lake-district-borrowdale-sheep-farm-sale-fight.
Also, I have recently retired from a company which provides services to many organisations, and one of its contracts is with the National Trust. I won't say what services my ex-employer provides to the Trust because that would identify them and break confidentiality, but I know my ex-employer to be ethical, and deliver value for money. So it was a surprise that the contract with the Trust rapidly developed into a so-called 'troubled' contract, with one unreasonable demand after another, the Trust exploiting any loophole they could find in the contract, and nobody in the office wanting to work with them because they were horrid to boot. My employer is just hanging on till the end of the contract and then certainly will not be looking to renew it.
It's all a far cry from the warm supportive view I had of this Charity a few years ago. :-((