Four [perhaps] plausible explanations in no particular order of importance.<p>1. <i>Ars</i> is written for general readers, i.e. it ain&#x27;t a refereed technical journal.<p>2. Though there will be only one Will Shakespeare, the English language licenses authors to coin words [and quine quines].<p>3. Usage is hard, even when referencing the scientific &quot;km&#x2F;h&quot;.<p>4. Bespoke fact checking is expensive and the internet makes all grammar errors shallow.<p>My take is that while accurate attention to the specification of velocities is critical to space travel it is not nearly so to the thrust of the article. Boosting research there would little lift the major point. [caveat] I admit to the belief it&#x27;s almost certainly a calculated mixture of time&#x2F;money investment relative to the intellectual payload and the magazine&#x27;s mission.