In both cases, I faced steep /uphill/ in terms of GTD-traction, engagement, sustained focus, smaller-than-expected job market  .. but why I held on to c++ but abandoned c#?
 actually c# was easier than c++ in GTD-traction, entry barrier, opacity
Reason: GUI — 95% of the c# jobs I saw were GUI but GUI is not something I decided to take on. The server-side c# job market has remained extremely small.
Reason: in 2015 after Qz, I made the conscious decision to refocus on c++. I then gained some traction in GTD and IV, enough to get into RTS. By then, it was very natural for me to hold on to c++.
— minor reasons
Reason: west coast coding tests — python and c/c++ are popular