I agree that a Hard SF ought not to colour space Blue, unless it is there to emphasis the grandeur of it. I like the darkness that is conveyed through the different architecture and style that comes with cyberpunk. If everything would be strict line drawings, then I think we would end up with Terradyne or early GURPS Space.
Sure, it is not likely that we are going to see a total break with the past, as suggested in some of Shy's work. But, I think the idea to give the impression something is really different here. Imagine what was the impression of immigrants from some backwater in the 1920s and arriving in New York. The result is the same, as the Science Fiction of the period depicts. There is a sense of wonder associated with the collision of modernity and tradition.
Likewise, to point out the background to the milieu is not like "Minority Report" (sans Psi), it is much more like Robinson, Gibson and Stirling...that is cyberpunk. To draw realistically would require a Space Artist, not a Gaming artist. I hope that Traveller can again achieve that balance, for me, as in seen in past threads. I do like realistic but not cartoonish.
So take Shy's work, as a way invoking wonder with the Spectactular not the speculative. I would not recommend it for Milieu 2100 but certainly some of the ruined cities of the 3I, post-Black War...why not. The future need not be shiny and clean, that I think is the image of the 1950s. If anything, we have seen the displacement and the environmental crisis that mankind now faces makes the cyberpunk appearance more realistic.