"to condemn to the place opposite of heaven"
That would be the full strength version of 'darn'.
The reason the words discussed are part of the larger list is that each person defines "moderation" differently. And then there are those who believe that moderation is something that other people should observe... but not them.
Unfortunately, due to the continued use of profanity by some, but not all, of the membership, the zero-tolerance policy has been adopted. And while not every post can be read and dealt with, those who break this rule over and over again can be, and have been, banned fropm TF.