It's not immediately clear how "armchair rationalists" would be more predisposed to affective death spirals than instrumental rationalists.

If you take it as axiomatic that instrumental rationalists are putting labor and effort into the material manifestations of instrumental rationality whereas 'armchair' rationalists merely discuss these ideas, then it becomes a necessity that the former be 'more rational' than the latter. And moreover, relegating the topic to a point of discourse without instantiation can be a form of affective death spiral.

Not that I necessarily agree with anything else in this post or thread -- just commenting on that point.