I would be perfectly willing to see a show like Cosmos allow a few minutes to a Creationist scientist... If they could present their views in a way that actually tackles science head-on rather than end-run around it. That means not taking a holy book as ineffable proof, going smoothly from premise to conclusion without swerving, offering strong, confirmed, positive evidence of the hypothesis (rather than, say, suggesting evolution is "false" because of potential gaps in the fossil record), and not trying to grind Occam's Razor into bluntness.
I would actually quite respect an actual scientist who could do that. But the fact is that while there might be "so many scientists who simply do not accept Darwinian evolution" from the ludicrously subjective POV that underlines a term like "so many", there's an overwhelming majority of scientists in all fields both closely and tangentially related to evolutionary biology who think Creationism (especially "Young Earth" Creationism) is completely without merit; more, the most vocal, public, and eager proponents of "scientific" Creationism would almost certainly fail to prevent their views as I describe above.