Its not bullying the devs to point out to them the massive GDPR violations of their software and to give them hell for sweeping it under the rug and literally say they won’t do anything to fix it.

It is. The data is in the DB and filesystem and can be manually removed. Having a button that does it is a convenience. It's the instance operator who will be in trouble if they don't. The code is provided with a license that literally says

THERE IS NO WARRANTY FOR THE PROGRAM

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES

You are using it and/or hosting it at your own peril.

And the devs said this

So there is no legal nor moral responsibility to implement any features that you personally want. However you are free to:

• Implement the feature yourself
• Pay someone else to implement it
• Stop using Lemmy and use one of countless alternative platforms instead

Then the fediverse erupted and made blog posts, toots, @'ed the devs directly, etc.

Also Open Source Maintainers Owe You Nothing. Interalise that. They owe use fucking nothing - except maybe the respect we show them and if none is shown, they don't owe any respect back.