One of the advantages of using a Kanban board for tracking scrum is that it identify bottlenecks in the process. The Kanban board has an interesting way to stop this - putting a limit on the amount of tickets that can be in a column at any given time.
Putting a WIP limit prevents too much work piling up. The team ought to be doing what it can to keep the flow going smoothly. It helps eliminate bottlenecks by preventing issues from piling up.
It also serves as a reminder to the team of collective commitment. That we are all in it together, and blockers affect everyone. Tickets stuck in analysis, development, or testing all have the same outcome - that feature doesn't get out. And given business value determines ranking order, the tickets in WIP are more valuable than tickets that are on the backlog.