Public access satellites. The FCC requires broadcast licensees to demonstrate that they're acting "in the public interest". Should private rocket launches have to give a minimum amount of their payload to research and non-profit purposes?
The elephant in the room is that launching one Hubble per year to a Hubble-like orbit only uses about 1% of SpaceX's current annual demonstrated launch capacity, and the actual reason people are upset has little to do with the actual impact on astronomy and more do with wanting to punish a certain CEO. One new space telescope every year would completely revolutionize the field, yet he'd barely notice. Better think of something else.
https://en.wikipedia.org/wiki/2012_National_Reconnaissance_O...
If we instead design something to be mass-produced at a cost more commensurate with that of a Falcon 9 launch, then it may well be much better than Hubble in terms of bang for the buck, but it won't be as capable as Hubble in absolute terms. Even so, although Falcon 9 is very cost effective per unit weight compared to past rockets, it does not have a large payload volume compared to launch vehicles used for previous large space telescopes, and volume is usually what you need for space telescopes (because big mirrors are constrained by volume, not weight).
Once Starship becomes fully operational it will completely transform the landscape because it is not only low cost but the interior payload bay volume is much larger than existing rockets in all dimensions.