Steve Jobs did want to use Intel's x86 design in the iPhone and iPad according to Walter Isaacson's biography of the man himself. But Jobs, who moved Apple away from the PowerPC architecture to Intel's in 2005, simply wasn't happy with the way Intel did business.
He is quoted as saying "There were two reasons we didn't go with them. One was that they [Intel] are just really slow. They're like a steamship, not very flexible. We're used to going pretty fast. Second is that we just didn't want to teach them everything, which they could go and sell to our competitors."
He added that Apple wanted to help intel but they didn't listen much. In the end, Apple purchased P.A. Semi and Intrinsity and embraced UK-based ARM architecture for its A4 and A5 system on chips.
Apple adopting ARM chipsets for the iPhone and the iPad proved to be a watershed moment, one which forced Intel to change the focus from being a pure performance beast towards power consumption, something the company always considered as a secondary worry.
Thanks partly to Apple, ARM is now a more formidable opponent to Intel than AMD, and is on the verge of rivalling the company in more traditional markets like servers and desktops.