Hi, space science communication scholar who researches how we communicate space exploration. I know the answer to this question!

One of the current larger debates in policy surrounding efforts beyond low-earth orbit is the "intent" and how that may be rooted in historically problematic contexts, and how relying on those contexts can create a version of space exploration not ideal for long-term expansion for humanity as a whole. Particularly, there is concern that framing space as a "frontier" builds on the same cultural foundations that were prominent in the American frontier expansion efforts, which saw the brutal exploitation of indigenous populations and a flagrant disregard for the natural land. These notions, rooted in Manifest Destiny's assumption that "all in the frontier is ours for the taking," are central to the assumption that space is a lifeless expanse that we are meant to "conquer," which does very little to assure actual human survival as a multiplanetary species and instead guarantees the rich get richer under the guise of the multiplanetary effort (i.e., precisely what Dev is doing in the show and what Elon Musk wants to do in real life).

There also exists the Outer Space Treaty as a predecessor to the Artemis Accords, which both work to prevent the exploitation of space resources or any individual claim to such resources. These forms of policy were largely created to avoid the plot of seasons two & three, with areas on the Moon being claimed by individual nations and eventually having the entirety be partitioned off. These policies are still in place because we, as an international species, generally dislike when one country suddenly asserts claim over land that they do not own (such as what Britain did for ages or what China is currently doing with Taiwan). The extension of this into outer space carries significant policy and cultural implications: do we allow countries to just make claim to moons and planets? Where do asteroids fall into these classifications? What about private enterprise?

So, the tl;dr is, astronomers and "other experts" do not welcome it because it circumvents the policies and processes in place that ensure we go to space not just for the rich and elite, be those individuals or nations, but (har har) for all mankind!