I dont know why the tournaments are run differently but i do have an opinion on the subject. I believe that the state tournament should be run like the regional tournament (with the semifinals on saturday). The state tournament is ridiculous for finalists. Yes i think its very nice idea to let finalists rest until their match at 6pm at night but i do not like it at all. By 6pm, some wrestlers are starting to get tired. Also, some finalists spend the day at their hotel where its easy to lose focus on whats ahead of them.
By having the semis on saturday, the wrestlers are forced to get up early and remain focused on the two matches before them. Plus the finalists are not nearly as rusty for their final matches, which leads to more exciting matches.