[Tit for Tat is] one of the few Memory-1 strategies that gracefully falls back to the appropriate Memory-0 strategy when faced with All-C or All-D.

I am not clear on how this is the case. It seems to me that the appropriate strategy when faced with any Memory-0 strategy is to go All-D, since your defections would optimize your own score while having no influence on the future behavior of your opponent. Tit for Tat does not default to All-D unless the opponent is All-D.