Elon Musk is “the biggest architect of our time,” says Jan Boelen

This is probably true but only in the sense that someone designing and building something slightly larger than human scale objects is an architect period. Some of this magazine's readers will be shocked by this because to them architect is a professional stance or practice (aka a cabal of sorts who enforce a certain aesthetic standard emanating from cosmopolitan universities, galleries, and where ever).

Design and architecture are activities and so is engineering. When someone performs the activity to some sort of recognisable standard then it is what it is. In sum, yes, of course he is an architect and its completely unsurprising and not worthy of mention!

"And it's all in the hands of one person."

Hmmm this quote really doesn’t help the credibility of Jan Boelen’s opinion.