@Chimaera ... I think you will find there are a LOT of people who feel working in plastic is better, for a number of reasons.
But ... what Rubicon has explained in some earlier posts, they started branching out into other areas (not just full-sized vehicle kits) and as a training medium for some of their junior sculptors, taking a design and making it in metal is just way cheaper. Molds for plastic injection are expensive to make (costing thousands of dollars). Molds for metal figures are almost free in comparison.
And sales are another factor. Once you sink your thousands into making the mold for plastic injection, how many sets of that thing must you sell to even break even? For metal molds, you break even almost immediately. SO you can sell a small number of blister packs and be making money, as opposed to needing to sell a trunkfull if the product had been plastic.
I think we can still expect vehicles and artillery and such to be plastics. But rolling forward, some of their figures will be metal because they don't expect to sell a lot of them, and thus cannot justify the expense of making a plastic mold.
