Here are some excerpts:
"...there are organizations that adapt Scrum for the wrong reasons, making it half-Agile, or even non-Agile... We might call these adaptations negative ScrumButs. They make a team's performance worse.
"But if you do your retrospectives well, they should lead to positive ScrumButs, making the team's performance better, which is great! It is the best part of Scrum! Scrum is a great starting point for many teams, just like XP and Kanban..."