I see where you’re coming from, and I appreciate you addressing this issue. I do think there are two differences for me in how I’m viewing the situation.
Perhaps foreign languages aren’t the best example, because (historically) most colleges have foreign language requirements that students need to fulfill, which would then pay for the faculty members’ salaries. But imagine a different field, like philosophy or linguistics ( 
), that are not required courses but that do not have much in the way of costs outside of humanties’ salaries. If there is insufficient demand by students at a non-flagship public university to pay for faculty salaries via their enrollment, then I would understand (though not be enthusiastic about) those programs being cut and only being offered at the flagship university.
In this instance, it’s not due to the non-flagship (or its students) being not worthy, but merely the economics of the issue. Ensuring that the state has at least one university where the offerings are strong (whether at the flagship, or at designated universities) is important to me, however, and I believe that there could be some subsidies for students who don’t live within commuting distance for programs that aren’t offered at their local Us to attend the flagship/designated schools with the offered fields.
So the above is where we differ. Where we might be more aligned, however, is in the vibe I get from some posters at CC that non-flagship Us are only for those who are too poor to go to a residential campus, academically inferior, or those who have other needs (health, family responsibilities, etc) that requires them to stay close to home. There are some terrific non-flagship publics, and unless they are highly ranked by USNWR, then they’re often not given any serious consideration by many on the boards. Of course, my comments are broad strokes and not reflective of all posters on CC, but it’s certainly a vibe that can come across when reading various threads on the forum.