Why are side sticks unpopular in sailplanes

I have heard from several very experienced pilots that it is easier to turn left than right, but in my thousands of hours of flying gliders, helicopters and various powered aircraft I have not found this to be true for me, a turn in either direction is the same other than if torque or LTE considerations. A glider has neither consideration. I do try to change thermal direction every other thermal. But I am confused as to why a pilot would think it is easier to turn in one direction.

On Thursday, February 23, 2017 at 2:45:04 PM UTC-8, Michael Opitz wrote:
Is it just me,
With the centre stick I fly with both hands,sometimes at the same
time,I
never think about it.
Gear,ballast vent on the right ,brakes ,trim release on left
Center stick has to be best.


OK, here my glider/slow speed analysis... At the speeds we fly, and
thus the relatively small circle diameters, the outboard wing will be
going marginally faster than the inboard wing. This means that it
creates more lift than the inboard wing due to relative speed alone,
and thus to keep from over-banking I find the need to apply a very
small amount of top aileron (against the turn) in order to keep a
stable bank angle and equalize the lift generated by both wings.
Because the outer wing goes faster, it also generates more drag as
well, so I find that I have to hold slight bottom rudder pressure
along with the top aileron in order to have the yaw string going
straight back.

So, now think about how that translates to operating the stick. With
a center stick, it is easier to make left turns and pull the stick
straight back towards your right elbow and right hip, than it is to
make right turns and be pushing the stick towards your left hip (all
while using your right hand). I have trained myself to fly with
either hand so that I use the opposite hand to the direction I am
thermalling in. George Moffat and Dick Johnson did this as well, so
I am not alone. This may partially explain why so many glider pilots
prefer to make left turns (always flying with their right hands). I
also know that George and Dick initiated right hand turns whenever
they could (in order to set the turn direction of a thermal) as a
competitive trick, knowing that most of their competitors would be
less comfortable in a right hand turn than they were.

Translate this to a gimballed side stick where all motion is in the
wrist, and then I don't believe that the ergonomics will preference
one turn direction over another, but with a center stick there are
good reasons to be able or want to switch hands on the stick.

RO