If NeXT hadn't produced a pre-emptively multitasking, memory protected, highly object oriented operating system and software development ecosystem, NeXT wouldn't have been acquired by Apple, and Apple wouldn't have had the key technology that has powered every major success they've had outside of the iPod in the last 10 years.
Remember that Apple wasn't shopping for Jobs, they were shopping for a modern OS; they only turned to NeXT after Gassée fucked-up their deal to buy Be.