Complex sentence: He continued to operate the school through the 1997 session, and then closed Clown College because the needs of the show had changed; the school was no longer profitable, nor necessary, as clowning had moved back into the mainstream of performing arts.
Split into simpler sentences: He continued to operate the school through the 1997 session, and then closed Clown College because the needs of the show had changed. The school was no longer profitable, nor necessary, as clowning had moved back into the mainstream of performing arts.