Even cynical me would think this isn't true, but willing to be shown differently.
However, I would be willing to believe that it's just laziness in how they are trying to protect themselves from something that has a similar look to known existing behaviors to malicious users. If an account shows any behavior that matches the same activity patterns that has been used by malicious users in the past, just shut down that account. The laziness comes from how they handle those accounts once flagged in that they just shut them down. The non-lazy method would probably not scale well, so they again chose the lazy way to not do anything else.
However, I would be willing to believe that it's just laziness in how they are trying to protect themselves from something that has a similar look to known existing behaviors to malicious users. If an account shows any behavior that matches the same activity patterns that has been used by malicious users in the past, just shut down that account. The laziness comes from how they handle those accounts once flagged in that they just shut them down. The non-lazy method would probably not scale well, so they again chose the lazy way to not do anything else.