Well he doesn't vape . . . and he comes across as anti-vaping to me. So.
In all likelihood what you read refers to Kanthal being used at a very high temperature. Vaping does not reach those high temps. Dry burning will, if a user is blasting a Kanthal coil at very high wattages, cause a coil to glow bright red (a known no-no). The solution is very simple. Always dry burn coils, no matter the wire type, so they only glow a very dull/dim orange.
You can use SS (stainless steel) 304, 316, 316L, 317L, 321, 430 or 904L for regular wattage vaping. Many do. It is NOT a wire for TC only.
You can also use Ni80 or Ni90 for wattage vaping. Again, many do.
I use SS316L and Ni80 in RBA's and with mech mods.
For me, Kanthal had a very noticeable metallic taste that I abhorred.