Besides, if you manage to find their issue you'd see carnage this decision caused for some of the customers. Even those with own runners found them swamped in jobs doomed to fail , blocking actually inportant pipelines.
Autodevops as a product feature targets very niche audience of teams running gitlab, but without dedicated DevOps team , it is by definition a very opinionated view on CI/CD and I can not see how it was acceptable to suddenly enable it on all existing projects on whole gitlab.com overnight.