Acorn needed more CPU power in its machines. 8-bit was no longer enough, so it was looking at 16-bit. Initially, we asked Intel for samples of their 80286 processor, but they refused. That's funny, because ARM is now perceived as a competitive threat to Intel, and you can trace that all the way back to the seminal moment when they refused to give us those samples. We somewhat arrogantly thought 'we can do this ourselves' and we decided to build our own 32-bit silicon. If Intel had been more generous, Acorn might have built its Archimedes computer around the 80286 processor -- it would have changed the whole landscape.
Read the whole interview at: http://engadget.com/2011/12/20/the-engadget-interview-arm-co-founder-john-biggs/