You can find Zamak parts (lightly to non stressed and low to no wear parts) in several high quality modern guns, just not the entire receiver like that Henry! It's a matter of what parts are made of the stuff and the fact it is all covered with fake brass to make it look like something it's not.
As far as modern "plastic" guns they are made of high quality polymers (not cheap plastics) that can cost more than metal castings, that stuff is much more durable than Zamak potmetal and is used to make the gun lighter not cheaper! Then they advertise the fact the guns are made of this material and indeed it one of the desirable selling points, the material is highlighted by the manufacturers as a very desirable feature by them unlike Henry who hides the potmetal under fake brass covers and then calls this material by their own silly names (brasslite????) for the stuff instead of telling what it actually is made of.
The point is not so much whether the rifle works well or not it's the deception behind it that stinks, Henry goes to great lengths to hide the fact that rifle is made of a Zinc based die casting by covering it with phony covers that they call by a phony made up name in an attempt to deceive the buyer of even that! The early rifles had the inside Zamk in the raw and it was not painted black to hide what it is, that along with some very cheap soft plastic parts on the outside (even the front sight!) didn't go over to well for them, they started using metal castings for the sights etc and also painted the receiver die casting black to make it look more like a durable rifle part. It's the company's deceptive practices from hiding Zinc die castings used for receivers to fake brass covers called by a catchy name (BRASS-lite) used to hide these parts in an attempt to dupe the buyer into thinking it actually is brass when clearly it's not, to their shady way of trying to make people believe they are a continuation of an old classic when clearly they have nothing to do with the classic except assuming the name. If a company will resort to that kind of deception what else might they do? It's about the deception more than anything else but then cheap die cast Zinc receivers don't do much for most of us either!
If a Zinc die casting covered by phony cast covers painted with a fake brass coating is your idea of a nice rifle for the price then that's your choice but some of us want better than that!