Your own statement illustrates the inherent biases Infrastructure Design Fiction strives to illuminate. Better for whom? The HST may be great for people living near the termini, and may produce a net lowering of carbon emissions, but what about all people who will never be able to afford that glossy future that hourly screams by their living room? Is a Tidal power system really clean energy if it disrupts an ecosystem?
Good design fiction can bring a lot to that conversation – whatever the bias of the author.