One place where thelyphthoric is listed is in The Compact Edition of the Oxford English Dictionary (1971, Oxford University Press), which marks it as both obsolete and a nonce word. Two citations appear, from 1780 and 1794, I think.
From arcamax.com, where the word was featured as "Today's Word" on 3/6/05: Today's word was the creation of Martin Madan, who wrote in 1780 "Thelyphthora or, A treatise on female ruin: in its causes, effects, consequences, prevention, and remedy." Madan put this word together from Greek thelus "woman" + phthora "destruction, ruin." Both Greek words have resisted efforts of etymologists to dissipate their mystery.
The word tendentious is used to describe something (an account, document, depiction, Wikipedia article, etc.) that's biased. What adjective refers to a topic that's highly subject to such bias, even though it could be presented in a balanced way?
A word for "rejecting the old"? Good question. We have misoneism and the evidently synonymous misocainia for rejecting the new. It seems there should be something for a similar attitude with regard to the customary, or traditional. Starting with the same "mis(o)-" prefix, one might look for something related to the Greek "ethos." ('misethism"?) However, Google appears to be ignorant of such a word.
A "real word" that comes to mind is "progressivism." However, that seems to have a political connotation, doesn't it? Perhaps an exploration of its synonyms?