Exactly. A muck raker was someone who had to rake up animal poo, especially horse turds and bedding, before the automobile era.
They were muck rakers, not rackers.
To rake up muck was to stir up sh**.
One's Rack of Muck is to: Acummulate or achieve something, typically a score or amount.
The site may be to show off one's resume of stirring up sh**.
Very Leftist.