You don't have to agree with me about ammeters. It's a free country, and you can use whatever you want in your truck. All I can do is to inform you of the potential safety hazards of this design.
From a systems design standpoint, they are a single point of failure - another reason they aren't good. There have been various designs like the inductive, the fused or the shunt ammeters - but they still have a basic problem that all the current has to go through the big wire feeding whatever ammeter design you have.
If there is somehow a short in this wire - anywhere along the wire, the truck dies - no matter what ammeter design it has. A short will usually melt the large feed wire going from the alternator to the ammeter. If you want to find an example of an ammeter-type design failure, all you usually have to do is look for a melted feed wire in a junkyard vehicle.
