Firmly identifying yourself with a position, especially with a cute little word, tends to lead to that, yes. I would definitely avoid using "deathist," "lifeist," etc.
It was a very brief moment in the conversation, not even remarked upon by anyone. It did make me think of it in an entirely new light, though. They were coming up with defenses partly because, if I was right about 'death being a bad thing', then there would be a significant amount of social policy decisions that need to be overturned or changed: politics rears its ugly head. Even without theism, decades of acceptance, etc., it will be a dangerous topic.
ETA: There is now a third thread, so send new comments there.
Since the first thread has exceeded 500 comments, it seems time for a new one, with Eliezer's just-posted Chapter 33 & 34 to kick things off.
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