GitHub has a formidable monopoly on source code hosting, thanks to network effects alone. I don't think there's a realistic case you can make today along the lines of your first bullet point that could convince a career-minded developer to switch away.
Direct competition against GitHub is barely worth contemplating; the practical path I see for replacing GitHub must be more indirect:
1. Some nonprofit foundation spins up a GitHub alternative focused on transparency and strong data privacy protections. This alternative has only a small fraction of GitHub's most crucial features.
2. A major FOSS project---which values the principles of the new alternative over the practical benefits of GitHub---switches away from GitHub.
3. Satellite projects reexamine their use of GitHub and slowly start switching over as well. The new hosting service incrementally adds features in response to demands from the growing userbase.
Steps 1 and especially 2 will require motivation by philosophical arguments, even if I agree that the linked article's execution wasn't perfect.
Not so much that I am saying philosophical arguments are wrong, they need to be had and presented, in this case I even find myself inclined to agree with them in some respects.
Simply, I'm highlighting what I believe to be crucial in giving the philosophical argument some teeth in purpose and next steps.
If the friction cost is low to do the right thing, then doing the right thing becomes extremely palatable
Direct competition against GitHub is barely worth contemplating; the practical path I see for replacing GitHub must be more indirect:
1. Some nonprofit foundation spins up a GitHub alternative focused on transparency and strong data privacy protections. This alternative has only a small fraction of GitHub's most crucial features.
2. A major FOSS project---which values the principles of the new alternative over the practical benefits of GitHub---switches away from GitHub.
3. Satellite projects reexamine their use of GitHub and slowly start switching over as well. The new hosting service incrementally adds features in response to demands from the growing userbase.
Steps 1 and especially 2 will require motivation by philosophical arguments, even if I agree that the linked article's execution wasn't perfect.