While completing Titan victory is difficult, than doesn't mean a Titan deck is at a disadvantage.
1.) Titan cards are powerful in their own right. There are a couple of good ways of drawing them, and they are quite powerful uncommon cards for relatively little cost.
2.) Titan cards fit perfectly inside Unliving decks, to the point where there is no reason not to include them, even if you aren't trying to for the Titan victory. This goes along with #1 but, the uncommon Titan cards rock. If you show me an Unliving deck that doesn't include the majority if not all of the Titan cards, I will laugh at you because you don't know how to build a deck with good cards. Titan cards aren't at a disadvantage.
Having the Titan victory available is just a nice bonus for Unliving decks, if you happen to get lucky enough to get it, but you don't need to reward them (people who use Unliving decks) even more for simply putting good cards in their deck.