The immutable law of celebrity states that if you are famous or known by the masses, you can sell them nearly any product you want just so long as it fits in with your brand. In other words, mass validation validates everything that they do, regardless of if it is real or fake good or bad.
Celebrity brings credibility even when credibility may be absent. For example if a rapper or Fake Artists say in their music that they are going to spray up your block, if they are famous, that is acceptable. People may even buy it because it fits in with a brand or fundamental human need to feel powerful. The power of the brand provides that power, but not the individual themselves. So if the individual themselves has no experience in spraying up the block, it doesn't matter.