[prutschman]

I think they're referring to the fact that there is one dimensionless base unit already standardized in SI: the mole. There aren't two length units, so there "shouldn't be" two dimensionless ones.

(Whether they were trying to be funny or not I couldn't tell you.)

[gerdesj]

It's a mol not a mole (sounds the same)

lol (or is that lole?)

"they" are not trying to amuse anyone.

[prutschman]

The "mole" is the unit, "mol" is the symbol for the unit, like with "kilogram" and "kg".

[drdeca]

How do you know that lalaithion was not trying to amuse anyone?