Here are some explanations:
1) Light dilutes in strength as distance^2.
2) The dust between the stars blocks the light.
3) The expanding Universe "reddens" the starlight to longer wavelengths, since space expands as the light waves pass through it.
Why are all of these wrong or incomplete? E.g., for number 3, why then is the night sky not brilliant at long wavelengths?
What is the most complete explanation, and what poet found the answer?