Need is definitely too strong a word, but I think we can agree that uv has so far been the best solution to a problem that plagued python development for a really long time.

Part of the reason Astral as a team is so well liked is precisely because they are not part of the main fold or related to "Core Python"; they are an independent vendor, one that delivered high quality code and listened directly to users and their own (extensive) experience to do so, and they succeeded at that repeatedly. Python packaging has {been seen as, actually been} miserable for years, and so by the same token the capacity to believe in/buy into solutions from the "core project" has dwindled. "If it took Astral to fix it, why would it be any different going forward?"

So that's all it really comes down to; uv isn't loved just because it's great but because it is in good hands. This real/perceived change of hands pretty much explains all the downstream responses to the news that you see in this thread. Regardless of who bought them, any fork is going to have very, very big shoes to fill, and filling those shoes appropriately is the big worry.