Seems they are offering a metric line but in brass. This doesn't compete well with the foreign steel cased. I always thought 10mm in steel at a cheap price might be a good option. Will steel handle higher pressures better?
I think there are three factors at play here. First, US mfg's want to maintain or build a reputation of quality, well-built ammo. Brass helps reinforce that, where steel screams cheap to consumers.
Second, steel ammo is less reliable (http://www.gunnuts.net/2013/04/08/handgun-steel-cased-ammo-test/) in general than brass ammo.
Third, the US market is heavily populated with reloaders compared to other markets. This matters to some consumers (most of us here I would guess), and it matters to gun stores with ranges. They make a good extra margin selling once fired brass to re-man companies.