"Duck" is also a brand name that sells it, so even if you don't believe his "duck cloth" theory, calling it that definitely can be objectively correct (if a little !hailcorporate).

(Edit: i just checked and the duck cloth theory seems correct, BTW.)

A bit of both really I guess.

Grew up calling it duck tape, later learned the "correct" name was duct tape and changed my ways (would correct people too), then even later worked construction and learned it's actually really bad for ducts (there's a proper foil-backed "duct tape" for that) and the original name was actually duck all along! So now I use duck tape to make it clear I mean the plasticy mesh tape that Red Green found so handy.

It's my a tiny crusade against what I consider a misnomer, plus it's more fun to say!

Here's a meme I just made if anyone wants to join the silly totally worthy cause