This is a pretty tough statement to defend. Take a look at the myriad of open source projects, or just limit it to Apache’s http://apache.org/index.html#projects-list and you’ll see a bunch of “empty emacs buffer” projects with a long audit trail of agile development. Not necessarily scrum.
The kind of work that good engineers thrive on - a hard problem starting with en empty Emacs buffer - is something that the methodology merchants have never experienced themselves. The only product they ever shipped is the methodology itself!
I say this as a one-time “certified scrum master”.