But that’s exactly the trap that’s kept it sidelined for years: we’ll support it once it proves itself, but it can’t prove itself because we don’t support it. That’s circular logic, and it’s why Hardcore has never reached its full potential.
That's not what I'm saying, this whole idea that it's circular logic is based on your misunderstanding of my argument. I'm making a clear distinction between the poorly supported version and the properly supported version. The way I see it, is that the poorly supported version has to prove itself, because it's essentially of a quality level that you'd expect from portal experiences. You'd not add every portal experience to the main menu either, unless it's really popular.
The properly supported version does not have the same necessity to prove itself, because the quality bar is much higher. Besides, the fact that Battlefield Studios would choose to support it, is justification to add it to the main menu in and of itself. Because like you said, why would they put development time, only for them to bury the game mode.
It's simply comes down to Battlefield Studios choosing to invest in the game mode. The point here is that they may have other considerations than I do, for why they may choose, or not choose to support it.
That visibility creates the very justification and developer attention you claim is missing.
Again, that's twisting things around. They first have to develop it (the properly supported version) and then they can add it to the main menu. Obviously after they've put in the effort and it's added, they have to continue supporting it based on player feedback. If they don't do it in this order, there's a sizeable part of the community that perhaps hasn't played hardcore before, gives it a try, walks away disappointed and never comes back.