This means that post-Steve Apple will be fundamentally different -- but it can still be successful. The best organizations spawn generations of great leaders, each with different styles and different visions. Rather than attempting to replace Steve with Steve Lite, the company should chart a new legacy within the culture and guiding principles that Steve built.
An admittedly simplistic and imperfect analogy here, but bear with me: the United States prospered long after the Founding Fathers left the scene, in large part because they established powerful and enduring principles for their successors. And every now and then, a truly great, Non-Founder leader emerged to reshape the country for a new era. Lincoln, for instance. Does anyone fault Lincoln for not being Thomas Jefferson?