Perhaps re-evaluate the yardstick which you're using to measure pick-able nits?
I hold Mr. Monroe in high esteem, as his humor is often smart and spot-on with the science. I hope this lapse is temporary.
Since you're obviously passionate about the subject tho, perhaps you could help me understand the error better? I dunno much more about the Planck length than that most places offer them in 8 and 12 foot, and pressure treated costs extra.
So just what is it then and how is it we can still shoot the tortoise with an arrow?
What would you propose? I think it is primarily a boundary, but conceptually I can see it used as a measure and rhetorical vehicle as well. Without being a physicist that is.
The Planck length is more than just a unit. It can be derived as the point where quantum mechanics and general relativity conflict. Planck-wavelength light is its own black hole.
Which does not mean that the Planck length is a fundamental unit, but it's the starting point for some beyond-the-Standard-Model physics. Most popularly, Loop Quantum Gravity (the main alternative to string theory) does use the Planck length as its fundamental granularity of space-time.
The fact is that most people have no business having an opinion on String Theory vs Loop Quantum Gravity. But it makes good copy to play it as a David-vs-Goliath story in popular science publications. And those publications are a double-edged sword. For a few, they are a crucial stepping-stone into deciding on science as a career (even though vanishingly few will do fundamental physics). For the many, they are entertainment, and leave them squarely at the top of Mount Stupid[1].
Munroe is well past Mount Stupid, and knows everything I've just said. But it's a trope he'll play with on his way to some other educational/entertainment end. He's explicitly referring to "quantum foam", a property of Loop Quantum Gravity, which does include P_l as a fundamental unit.
As I said, I'm always wary of that kind of popular science. It's hard for me to tell whether it's a net benefit, whether it informs more than it misinforms. But I can say that I would not have gone into science without starting there, even though I was told an awful lot of lies in my early science education.