Nobody loves talking to a genuinely morose person

People only like the genuine people they agree with.

I just had a conversation with someone who disagreed with me on almost every topic. When it was done I thanked them for disagreeing with me civilly.

you're obviously free to believe whatever nonsense you want, but it says more about your lack of social skill than anything approaching a truth.

I go to a D&D group with 2 devout christians, 1 agnostic, 1 atheist, and 1 hindu.

We've all been good friends for probably 15 years at this point. Do you think we all agree?

maybe stop limiting yourself.

You specified that they disagreed with you "civilly", which generally means they behaved in a way you agreed with, even if they had differing opinions on non-behavior topics. People still only like genuine people when the genuineness includes behavior they like.

that's not the definition of the word civilly. words have meanings. Generally speaking, when you find yourself redefining the meaning of words it's a strong indicator that your argument is poor.