Comment by QuadmasterXLII

To answer your literal question of "why do people think..."

For a while there was a widespread standing principle to not assume malice for actions that could be explained as a simple mistake. If only one person follows this policy, it's great. However, so many people were following this policy that it created massive incentives to disguise profit motivated malice as explainable accidents. We're in the midst of a massive backswing against this.

So, there is very little taste for patience when agents of ycombinator make mistakes that benefit a16z such as accidentally removing them from the title of a negative article, due to the billions of dollars entangling ycombinator with the reputation of a16z. This is not because it wasn't an accident- it's because any culture of patience with this will lead (and has led) to an explosion of copycat whoopsies.