@david blocking you instantly is still a nicer outcome than
1. misread you completely and explode into rage, sending reports, demanding that you kneel and answer to your evil deeds of [something insane that you didn't even do]
2. stalk you, spam you, post IP loggers as bait for you
And although there are of nicer things to want, what's important is the direction rather than the goal. You can't move people to a goal, but only in a direction. That's why the slippery slope is 100% a real phenomenon and not a fallacy, which people rightly worry about. If you discourage blocking, you'll get more nice direct contacts, but also more insane reactions that will make you wish you'd been blocked instead.