I've been using Logic since the Atari days, and I certainly don't mean to belittle the contributions of eMagic! I'm less familiar with the linage of Final Cut, but I'm sure whoever developed that before Apple did fantastic work.
But, though it's become a cliche in this context, I think what makes these products world-changing is Apple's vision. [EDIT: actually, now that I think about it, it's not their vision. It's their business model (the very thing the OP was deriding). Apple sells hardware and can use software as a loss leader. So it's able to sell Logic and Final Cut for much less than when they were the sole income of their respective companies] After Apple bought Final Cut and Logic, they slashed prices, refined the interfaces to make them much more approachable, and gave users a way to migrate from simple iApps, to Express versions, to the full-blown Studio packages.
This ease of use, low cost, and easy migration vision of Apple's all works together to democratize the creation of media. As a platform, it places an emphasis on the creation of media, not merely the consumption of it.
That's what I find world-changing about it, and I think its all stuff that's happened post-Apple-buyout. But I'd love to hear more about any similar efforts made before Apple bought these products.