Not sure if it's a rhetorical question, but I'll answer anyway.
That's often when it is most useful. It alerts people that it may be an unknown, new, or fringe source. You don't see them often because the bot helps people report remove them quickly.
Because one of the mods programmed the bot and is really proud of their accomplishment. Their ego has blinded them to the problems they are causing.
I agree that it’s good to be proud of your programming accomplishments. I also think it’s really fucked to abuse positions of power and ignore community input.