Traditionalists have been occasionally misunderstood, by those with shallow understanding of Traditional doctrines, as being prone to "nostalgia" in terms of idealizing particularly ancient and medieval history, and prone to "optimism" in terms of expecting the Dark Age to roll over into a new Golden Age.
Regarding "nostalgia": As noted, the Dark Age corresponds approximately to our timeline of recorded history. Our "ancient" and "medieval" periods still exist in the "Dark Age," and are rife with anti-Traditional forces. They are only relatively more "Traditional" in contrast to the aberrations of our "Modern" period, particularly the excesses of the post "Enlightenment" period. The tide of Traditional and anti-Traditional forces occasionally fluctuates, and at a level beyond the imposition of human "will" in the matter. There are traditional doctrines of phases of the Kali Yuga. By one Traditional system, the "Twilight" phase of the Kali Yuga began in 1939. Much could be said about this.
Regarding "optimism": Traditional doctrines are almost unanimous that the transition from one phase of major cosmological cycles to another is cataclysmic in nature. Both Guenon and Evola disparaged their over-eager followers who had romantic ideas about forming "elite" cadres in hopes of being the standard-bearers of "Tradition" into the next era. Aside from the cosmic time scales involved, meaning none of us reading this will likely live to see it, the cataclysmic nature of the transition is such that few would survive the transition even if they lived long enough to see its arrival.
Whatever "nostalgia" or idealization of the knowable past there may be is highly conditional. Whatever "optimism" might be warranted is abstract and impersonal in nature. Misanthropy and "pessimism" is generally warranted. Nihilism might only be inconvenienced by a modicum of abstract, coldly impersonal metaphysics within a transient spatio-temporal threshing machine.