all the more中的the不是定冠词,而是用在比较接或最高级前表示强调的副词。all the more是习语,是个副词性结构。所以 made it all the more profitable to work longer.it为形式宾语,to work longer为真正宾语,all the more profitable 为形容词短语作宾补。
all the more [副] 更加,越发 / His excuse made her all the more angry. 他的辩白使得她更加生气。 / The letter from my mother made me happy all the more because I was homesick. 因为我在想家,母亲的来信越发使我高兴。(摘自外研社、建宏《英汉多功能词典》1997年1月第1版)