After my wife spent 13 years with our first spaniel tucked down the side of her chair we resolved things would be different with our subsequent cockers.
None of them since have been allowed on the furniture, and none have attempted to break the rules after initial training. None of them held it against us, or have been the worse for having boundaries.
Our current cocker, young William (now 4 months) is not allowed on our laps or on the chairs, if we want to cuddle him, whilst he is still a puppy, we get on the floor. Dogs are easily trained not to jump on furniture, but it does require consistency by all the household members. 'Furniture' dogs are simply being indulged by their owners, more for the benefit of their owners I suspect.