Quite a few Hams have used cable TV coax at HF with good results.
The problems with steel at HF & MF are real, but I have only really seen them manifested in equipment in the region of tens of kW, & then mainly where someone has inadvertently swapped a cad plated steel screw for a nickel plated brass one.
At low power levels, there is obviously a proprtional loss, but it is often ignored, & the cables used.
"Cable TV coax" can mean many things, from 75 Ohm "hardline", down to plain old RG6.
I still have most of a roll of RG6 cable I used to connect the antenna & splitters for my TV set.
It is pretty much the standard used for external terrestrial TV antenna work in Oz.
The dB/100m loss is better than RG59, but not as good as the old, horribly flimsy semi-air cored coax which was the previous standard.
It does have a much heavier shield, is rugged, & the "compression" "f" connectors are light years ahead of the "Belling Lee" & simple "clamp & screw terminal" things we used to use.