Why is Scrum iteration called a Sprint? I'd say that a sprint implies commitment, hard working, willingness to finish all the tasks taken into the sprint by the end of the sprint. On the other hand Scrum doesn't require a team to complete all the tasks taken into the Sprint.

Jeff Sutherland, one of the creators of Scrum, provides an answer in his book Scrum: The Art of Doing Twice the Work in Half the Time:

> And so my team embarked on what we called "Sprints". We called them that because the name evoked a quality of intensity. We were going to work all out for a short period of time and then stop to see where we were.

In Scrum, Sprints have some of the characteristics that you describe. Scrum has five values - commitment, courage, focus, openness, and respect. The values of commitment and focus align with what you would expect from a Sprint, but the commitment is to the Sprint Goal rather than to completing all of the Product Backlog Items or the Sprint Backlog.