That also means every event in which Shri Ram or Mata Sita were involved would provide a Dharm, yet no religious leader has made efforts to tell Hindus about this.
After the VADH of Tadaka, Marechi was sent to Lanka to persuade and bring Ravan for negotiations in a fast Vimaan which looked like an arrow. King Janak also participated in the deliberations and one of the things that were agreed was that Weapon of Mass Destruction, Shiv Dhanush would be dismantled immediately. Janak decided that he would arrange a swambar, where the king/prince, whose team could dismantle Shiv Dhanush, would be married to Sita. Read : RAMAYAN AND HISTORY
Now the Dharm today and in Treta Yug was and IS the SAME. Such love need to be pursued to the logical conclusion. Ram had also assessed that Sita was also in love with him. We know that Ram/Lakshman were accompanying Sage Vishvamitra and they had been invited to SEE (not participate in) the swambar. Ram could have directly or indirectly indicated to Sage Vishvamitra his intention to participate in the swambar, but he chooses not to do so.
As earlier said Ram/Lakshman was on a mission which was being pursued by Sage Vishvamitra, and the mission was not complete. The mission would be complete after satisfactory dismantling of Shiv Dhanush, and maximum number of kingdoms endorsing/consenting to dismantling of Shiv Dhanush. Remember every Yug had its own way of recording a consent or decent. Kings and prince’s participation in the contest would automatically get registered as consent. As such, since Ram was on a serious humanitarian mission, his Dharm forbid him to think of other things except the mission.
When a person is on a mission for Humanity, Nation building, he/she is supposed to remain focused on the mission and under NO circumstances deviate/expect/accept any personal benefit out of it. Shri Ram did just that.