It strikes me that a couple of perceived benefits in having one-weight at a time in the semi-final matches are that the wrestlers get a little better opportunity to serve as the focus of fan attention during their particular match, rewarding them for their hard efforts in competing for a chance at a coveted state title; and that the fans can better direct their attention towards a particular match, instead of dividing their attention over several interesting matches.

From my own selfish perspective, I enjoyed the one-weight, at at time method - conceding that it certainly took considerably more time.