I wanted to link to Andrew Chen's recent article, Does every startup need a Steve Jobs, because it's a useful discussion about the differences between technical feasibility, design-led desirability, and business viability, a triplet productized by IDEO, and one that we also identified a decade ago at Razorfish (wow, it's really a decade ago!). As for the question in the title - no, I don't think that's the only way to create greatness, though clearly if you have Steve at your disposal, you could do worse than have him run everything. :)
Seriously though, at least in this consumer-targeted software business that I'm familiar with, it's crucially important to have those three principles well represented at every level of the business. Sure, it's possible to create a successful business with just two or perhaps even just one of those viewpoints, especially if you can get away with copying someone else but just doing it with better economics. However, to create something new and be successful, it'd be a mistake to ignore business, technology or design. Sadly, of the three, design is the one most commonly ignored. According to this interview of Ken Auletta of his new book, even Google ignores it, Marissa Mayer notwithstanding.
Anyway, what I'm particularly interested about is how can you marry great design with incremental, rapid iterations on the market. I'm pretty sure I've understood how to iterate out in the open with regards to technical work, and relatively comfortable with iteration regarding business aspects. I've yet to come up with a really convincing argument for iteration and design on a very granular basis - well, I can convince myself, but I'm having less success convincing designers. :) If anyone cares to share their secrets, I'd love to hear more.