It all depends on how an individual feels about the status quo.

A. You can be moderate because you believe moderate actions will bring about radical change, or

B. You can be a moderate because you believe things are good to some degree as they are, and any actions should result in moderate changes.

I'm inclined to believe the calls to moderate discourse come from the latter group. "Rational discourse" stands in opposition to "irrational discourse", with implied irrational demands.

In other words, if you can't see why group X would want something, you won't see anything group X does to get that as rational.