alt Hacker NewsMy branch is mine. Don't tell me what I can or can't do. I push WIP stuff all the time, to share code with others for discussion, to get the build to run in parallel while I keep working or just at the end of the day. I freely amend and will squashed before merging (we only allow a single commit per branch to go to master).
If I or someone else bases something off anything but master that's on them to rebased and keep up to date.
My philosophy is that once a PR is open, that's the point at which people should no longer feel free to treat their branch as their own. Even in groups that squash commits, it should still preserve the aggregate commit messages.
But until that PR is open? Totally with you. There is no obligation to "preserve history" up until that point.