Mud (sediment) is ugly to look at.

It suffocates fish by clogging their gills.

It is not fun to swim in.

It smothers habitats where fish and other water critters live.

It prevents fish from seeing their food or fishing lures.

It carries chemicals such as fertilizers and pesticides that are harmful to the environment and to people.

It also costs considerable sums of money to strain  it out of our waterways.