Not exactly damaging the reputation, pump and dump is definitely one way to earn. Even sometimes in stock market it does happen. Effects can be negative or positive depend on your situation. Others do earn while others experience losses. It does happen to coins which doesn't have a long term goal so we can call it shitcoin.
Really???
You know; stealing, mugging, holdap, carnapping, kidnap for ransom, dealing illegal drugs, human trafficking, etc. are ways to to earn as well? But do you realize these are wrong? Market manipulation (which what P&D is) is illegal and morally wrong!