One important note: Any loss of life you would take outside of damage, such as the effect of the Extort mechanic, would still reduce your life to 0. So it's still possible to lose with Ali on the board; it's just considerably more difficult.
As this card is not banned in Vintage or Legacy, it's still very possible to build a deck around Ali. Getting your hands on a play-set is certainly a pricey proposition, though, at over $50 a piece. will a deck based around him be as good as it once was? Not particularly, especially as a creature with no power and only 1 toughness. But he's still fun to play, and he's a valuable card for your collection.