I think it is wrong of charities to go beyond their remit, other than to ensure that employment conditions for their staff are beyond reproach.
I have cancelled my long-standing membership of Amnesty, as they became political, when previously they kept out of politics and campaigned for prisoners of conscience regardless of the circumstances. I now support Freedom From Torture, which AFAIK is sticking to that brief.
I think that charities who campaign for a cause should be legally obliged to support that cause and not to divert funds to other causes without ensuring that their supporters are on board with the changes. To use an extreme and hypothetical example I don't want to donate to Shelter in the cause of UK homelessness and find that I am supporting an alligator sanctuary in Alabama.
Oxfam has been particularly arrogant in this regard - banning the sale of games that feature women because there are no transwomen, for instance. this has nothing to do with famine relief or global poverty, which is supposedly what Oxfam exists to prevent. I'm not saying that I would never buy from them again, but I now take decluttered items to Relate or BHF instead of the Oxfam on my High Street, and if I had had a Direct Debit with them I would have cancelled it.
Considering the amount that big charities spend on PR this is a very basic error, I think. They seem to take their supporters for granted at best, and for fools at worst.