Yes but Python also isn't generally distributed the same way. You could argue the same about the C++ redistributable across Windows and even .Net (I think 4.0 r

Yes but Python also isn't generally distributed the same way. You could argue the same about the C++ redistributable across Windows and even .Net (I think 4.0 runs on XP), but malware for these are still executables. Silverlight may be the only common ground, but then that's the same as Flash, Acrobat or similar plugin. And as you say it certainly doesn't run in the browser on so many disparate systems making watering hole attacks not nearly as damaging if there were to be Python malware in the wild (and I'm sure there are).