So people can see when exactly the trade took place. This will also give an idea of the daily volume/activity for that pair. See example screenshot attached from crex.
I have a _variation_ on this, that might help.
If it is possible for development, if we hover over the TIMES on the TRADE HISTORY that we can see in any of the market pages, it would be nice if it would reveal the DATE belonging to the TIME that we can see. A cool addition to that, but it might be difficult to do, would be if the mouse pointer moving across the CHART could put an underline (or bold formatting) on the corresponding line in the TRADE HISTORY.