I too (like Eddie P) can see that, logically, the strap and even a tray combined with thumb & forefingers may be better: more precise. But when I learned to fly in the summer of 1976 in Baltimore, every one in the Radio Control Modelers of Baltimore Inc. flew thumbs only and I don't think anyone there had ever seen a strap. I tried a strap a few years ago but it felt too weird. I also tried to use the thumb & forefingers, too weird again.

Old dog, new trick syndrome, I guess.

RUFF, RUUUFFFFFF!