That might have influenced significantly in the selection of the Python users taking the survey: why answer a survey setup and sponsored by a private company you are not really familiar with and that you don't necessarily trust as a result?
There is also a second selection bias: the people who follow the PSF and the official python.org communication channels are probably nerdier than the average Python programmer. This is reflected in the OS statistics. The survey results suggests than 53% of the Python users do not use Windows at all.
On the scikit-learn online documentation, after removing the mobile traffic we have: Windows at 61%, macOS at 23% and Linux at 15%.
On stackoverflow, the primary OS statistics are: Windows at 47%, macOS at 27% and Linux at 23%.