Sadly this article doesn't mention the early ARM-based desktop computers Acorn produced: the Archimedes series (ARM 2, 3, StrongARM) and the RISC PC (ARM 600/700). They were instrumental in shaping me to be the developer I am today.
ARM processors try to find the sweet spot between small size, low power and high speed. By picking which pieces to include, which to leave out and which to optimize for size/power/speed the big licensees such as Apple, Qualcomm and Samsung can each choose there own sweet spots for the products they want to make.