Yeah there's two 'main' kinds of people who want a platform where users are able to post hate speech and reach "everyone" with it.
People who want to be hateful and want access to the targets of their hate. They want to upset people, they want to 'own the libs' or be able to toss slurs at minorities, and those things are unrewarding for them if they don't get to see how upset they've made their targets.
People who want to recruit people to being hateful. They want to convince normal people to share their prejudices and their biases, they want "debates" or would like to share "statistics" and are seeking a soapbox that can reach people who might find their views convincing.
This is a huge part of why defederation works, why platforms like Voat or Gab rarely thrive for very long. Being hateful in an echo chamber towards people who are outside the room is rarely fun for those folks, and very often results in in-fighting and fragmenting of the movement. Moderates and 'normies' are driven off because now they're a target rather than a participant or spectator.