Probably a silly question here (and I've asked it before), but why exactly do we only have dodgy download sites for Windows programs anyway? I mean, other plat

Probably a silly question here (and I've asked it before), but why exactly do we only have dodgy download sites for Windows programs anyway? I mean, other platforms have decent stores and download repositories. And games on Windows... well, you've got a lot of good sites and services there. Everything from Steam to Good Old Games to the average game mod or ROM hack download site is moderated and mostly kept free of adware and other crap. Is there really no one interested in providing a site or service that explicitly disallows bundling and ad supported crap (or that outright removes it from anything submitted to them)? Does no one with any ethics exist in this space?