I've asked the same question to a teacher in China. He told me that the character represents a man teaching other people archery skills. Think a little about that action. It has a deep mystical meaning. Other uses of the character are:
谢 /xiè/ 1.动词 文言 辞去官职。「谢官」 Verb: Classical language, Resigned from office. "Xie Guan" 2.动词 推辞；拒绝。 「辞 谢」 Verb: Decline; refuse. "Thank you" 3. 动词 辞别；离开。 「谢世」 Verb: Say goodbye; leave. "Xie Shi" 4. 动词 凋落；脱落。 「花 谢了」 Verb: Withering; falling off. "Flower thank you" 5. 动词 认错；表示歉意。 「谢罪」 Verb: Admit mistakes; apologize. "thank you" 6.名词 姓。 Noun: surname.