...there are some hams that will INSIST that it will not work just because the figures on a piece of paper concerning its effiency says it will not work...
Pointing out that some antennas are quite inefficient is not the same as saying they won't work,
for some definition of "work". Saying that hamsticks for 80m are at best a few percent efficient
doesn't mean that they can't make contacts, or that hamsticks for higher bands won't have
much better efficiency.
Same with coax - using RG-58 with 3dB of loss isn't the end of the world if that is what you have
on hand. In most cases the antenna will still work better up high with a lossy coax than indoors
at the rig with zero coax loss.
There is a continuum of trade-offs. I make plenty of contacts running 5 watts or less to a dipole,
and someone running 100 watts to a 5% efficient antenna can expect to do about as well. You
just won't be as strong as you would be if your antenna was radiating more of the power fed to it.
Twisted pair might not be the most convenient feedline, but when you are living in a remote
logging camp and the only wire available is what you can salvage from the blasting operations,
it is better than any amount of LMR-400 sitting hundreds of miles away that you don't have access to.
You do what you can and live with it. Don't assume that everyone has the same trade-offs among
convenience, cost and performance that you do. There is no "one right way" to do things, and
anyone who insists otherwise is somehow missing the big picture.