The businessman who abruptly quit as president of the La Scala orchestra Monday has said he was disgusted with the opera house’s unions. “Fedele Confalonieri, chairman of the Mediaset media conglomerate, also said the company might withdraw its financing of the orchestra. In an interview at Mediaset’s Rome offices, Mr. Confalonieri said the company had paid at least $700,000 a year for Sunday-morning concert broadcasts on one of its channels.”