Should there be standing water in this part of my dishwasher?
It's unintuitive, but understand that it's relatively easy to get most standing water removed, but very hard to get it all removed. A major reason for this is that you generally have to drain uphill. Dishwashers do that to prevent sewage from siphoning back into the basin. It's just not possible to empty that hose 100%. As such, some water from the rinse cycle (which should be relatively clean) will remain the dishwasher.