A wrestler is nothing if they can't draw heat from a crowd. If they're a babyface, that means building sympathy, support, and provoking a booming chorus of cheers whenever their music hits. For heels, the goal is the opposite, and if they're good at their job, they'll become a reviled, antagonistic foil for those on the other side, with the crowd desperate for their comeuppance.
Making an audience boo you is generally easier than convincing them to like you, but not all heel heat is created equally. Sometimes, an audience will jeer a wrestler not because of their effective heel work, but because they're sick of of them as a performer, and not just a character.
There's a huge difference between loving to hate a wrestler and wanting them to disappear completely. Some may argue that any reaction is a good reaction, but if a heel actively has viewers reaching for the remote control, they aren't fulfilling their role correctly, and wrestling history is littered with examples of 'go-away heat.'
Whether it's because they were pushed too hard, had unsavoury backstage reputations, or just plain sucked, each of these names provoked the wrong kind of hatred, leaving the fans exasperated by their mere presence...