Doesn't this simply fit the first-century model? That there be an equalizing out of the wealth? I mean, really, isn't the ploy that wealthy congregation be helping their less fortunate fellow-believers? What's actually wrong with that?
What's wrong with it is that there is nothing voluntary about it. The elders present it to everyone as if it was their own idea, it's not mentioned to them that the society demands it. They could save it in case of a future deficit, use it to purchase supplies for future conventions or save it for future remodeling, but that is not an option, it's "send us the money". In other religions the congregation decides how to spend every penny, they have control, in this religion there is no decision making at the local level, just the illusion of such. Everyone knows if mother asks it's not a request.