Why was Esau upset about losing the blessing but not the birthright?

Esau was upset about losing the blessing because it was something material, but the birthright never bothered him because it was something spiritual. The blessing carried material significance to him, while the spiritual birthright did not provoke the same concern or emotional reaction.

Les explains that Esau got so excited about missing the blessing because it was something material, whereas the birthright never did bother him because that was something spiritual. So the issue was not equal in Esau's mind: the material blessing was the part that upset him, while the spiritual birthright did not move him the same way. Les also says this helps settle these things in our mind, and then the next program would show how things progress after the deception by Jacob and his own mother.

Why did Esau get so excited about missing the blessing but not care about losing the birthright?

Esau became upset over the missing blessing because it was material and tangible, while the birthright never troubled him because it was spiritual. His grief focused on the physical benefit he lost, not the spiritual privilege he had already treated lightly.