I read "adhere to the sprint commitment" as being an undesirable aspect of Scrum that the author was complaining about, not something that Scrum is lacking.

It's certainly one of the bad parts of Scrum as commonly interpreted; c.f. http://www.peterkretzman.com/wp-content/uploads/2014/10/Aski....

(That's why newer docs tend to substitute "commitment" with "forecast", to clarify the Manifesto author's intent).