I notice that this thing you and others call empathy doesn't extend to the outgroup: if anybody doesn't subscribe to it, fuck 'em, is the general sentiment.
No idea! Well, I must assume good faith and believe you. To me it looks like you're labelling everybody you dislike as "probably a psychopath, best disposed of". I suppose that's consistent with saying they're not the outgroup, it's just a practical necessity or something.
In this instance of course what you're proposing is very mild: you think they should suffer one another's company - which you imagine would be a terrible experience. Unless you further imagine that they'd like it? But my impression was that you thought they'd have a bad time, and since they're your non-compassionate outgroup, you very compassionately don't care.
You read a bunch of things into what I wrote that simply are not there. I like plenty of people who would press the red button without hesitation. Their decision is their decision and my decision is mine. Might they “have a bad time?” Maybe. Maybe not. I’m certain I would have a terrible time, if I joined them in the majority.