You raised a lot of interesting talking points in this and I know there are some curation projects on Hive that has openly made a stand about cross posts. They say they don't want you to share your content any other place except on Hive. Once you start cross posting to othe chains, they will blacklist you on their curation.
Some others lean more towards saying that you can cross post, but the first post has to be published on Hive.
Well, the reason for the former is not so clear especially when a post published on Hive gets spread across various frontends like Peakd, Ecency, Proofofbrain & co.
What I know from all these is that If I have a post and I decide to cross post to 10 other chains, I will go ahead and do it. I just have to make sure that I will indicate that "the post is mine and cross posted to other places".
Of course, this means that I'm ready to do that while accepting that I may not get curated by folks who think I'm farming for sharing my own content in other places.
I can deal with that, as far as no one comes to downvote me for cross posting something that originally belongs to me.
I genuinely don't feel bitter about curators. They can use their vote to curate any post they like. However, I don't want anyone to dictate where I have to post my stuff. I can post my stuff wherever it will be accepted and where it aligns with the guideline of the chain or community.