I wonder why everybody isn`t using this antenna? .......

Because a rotatable yagi is usually better in
most cases. But people do run those...Probably
more set them up to be switchable, or even steerable,
instead of just one direction. I ran phased dipoles
on 40m, and they worked quite well. I switched
direction by changing feedline lengths. Some
use the "l/c" phaser boxes...But I can throw up
my A4 real quick, and do about 7 dbd?? or so, in any
direction. Kinda makes the phased dipoles a mute
point, except for maybe the lower bands.
If you connect with a harness, which I didn't do,
you need to transpose the feed for the 2nd antenna.
IE: reverse the feedline...That ladder line will
have a single twist if I remember correctly.

MK