Earmarks are not inherently evil.
If the money being spent is for a Constitional need, a Congressman would be derelict in his duty to his district by not trying to bring it's share of Federal spending into his district.
Hence, there are good and bad earmarks.
Distinguishing between the two is where the rub lies.
Paul got an earmark to help market wild shrimp. I don’t recall crustaceans being mentioned anywhere in the Constitution.