I also find the 12% fact hard to believe. IMHO lots of commercial software is still developed and runned on windows, and seing anything other than MSVC there is an exception. For games I'm thinking the situation is the same. So I would guess it alone is at least 20%.
Also the embedded SW development market is really big, and C/C++ is still dominant there. E.g. in automotive nearly all ECUs are pure C, using compilers that fall in the "others" category of this survey.
But I guess the issue could be the used sources here. E.g. embedded is in large parts a closed ecosystem with less visibility on the internet sites about programming (which are often very web-focused).
Also the embedded SW development market is really big, and C/C++ is still dominant there. E.g. in automotive nearly all ECUs are pure C, using compilers that fall in the "others" category of this survey.
But I guess the issue could be the used sources here. E.g. embedded is in large parts a closed ecosystem with less visibility on the internet sites about programming (which are often very web-focused).