Rocky;
The senior guy that is on a trip or otherwise unavailable has an issue with instantaneous open time or more runs. Running it three times a day allows guys time to look at it and put their requests in. It allows their seniority to have a little more control.
I like the way you think, but many of the guys that I fly with like it the way it is. You could put standing swap qualifiers in but most guys fear change.
It is doable as it is just a computer, but guys like you and I could then cherry pick that time, and the senior guys would have a harder time to nail down what they want. A few wrong swaps etc would cause a major uproar.