Many of Richard's failures can be chalked up to the fact that he's pretty easily fooled by appearances. If someone flatters him and tells him he's awesome, he believes them; he never stops to think about whether they might have an ulterior motive. It takes a lot of suffering for him to learn how to look through the surface and see the truth that lies underneath.
Several other characters in the play are also interested in figuring out how to interpret what they see. For instance, nature shows up again and again as something to be interpreted. Do the withered trees mean that the king is dead? Or that a new king is coming? Or that God is angry? Or nothing at all? Without a strong king, the kingdom is on shaky ground, so everyone is trying really hard to find meaning, a way to square the way things look with the way they are.
Even though Richard is unconscious of his image throughout the early part of the play, by the time he gives up his crown, he's become a master showman. He knows how to star in a big political drama.
He might not be great with language, but Henry Bolingbroke is excellent at public relations. He manages to get the people on his side even before leaving England, and he maximizes the damage of Richard's political mistakes.