Why does the world look "weary, stale, flat, unprofitable" to Hamlet? Is his attitude youthful rebellion, or a deeper wisdom?

Hamlet is melancholy for sure but I think we can find certain truths within his sadness and rebellion. Hamlet has understood that his world is inherently corrupt. Money and power of the corrupt are maintained at the expense of the good. The murder of Hamlet's father is but one example of this.