Worklist not showing escalated items

Recently I get more questions about the worklist for approvals. This is mailny because we direct users to look at the worklist and just rely on the emails (users tend to open them at home/phone and therefore have them marked as "read", and don't notice them anymore).

However, when a requisition is escalated, because the workflow item was not worked, that item is pulled out of the worklist.

The setup for escalations is that we just send an email to the approver(s), no re-assignment what so ever.

Why is the item not showing up under "Worklist", when the worklist-item clearly is still available for that user. As Worklist-administrator I can still find it for that user.