They launched it without addressing the obvious issues like spam and low-quality content. The easy migration from Instagram basically turned threads into... Instragram. Literally the same low quality posts and low quality engagement of Instagram transfered over. Seriously, have you ever read comments on Instagram? It's the bottom of the barrel in the every sense of the expression. That's Threads now.
Also, poetically threads on Threads are even harder to follow and navigate than Twitter.
Isnt instagram primarily used for.... pictures and images? I seen comments the times i have used it - the comments are generally very low quality and low brow.
I think both of your points are correct but a lot of celebrity types write straight up essays attached to some of their pictures - it's like where they get out everything they can't fit into 280 characters.