FOSS adware and spyware apps are rare because it’s trivial to fork it and remove the undesirable elements. Users have every incentive to use the ad-free and spyware-free forks, which eventually causes the superior user-friendly forks to overtake the originals. However, proprietary adware and spyware apps cannot be forked in the same way, preventing users from stripping out the ads and tracking. The ability to use, modify, and redistribute “trash software” allows anyone to transform FOSS with undesirable elements into excellent software by removing such elements, whereas proprietary “trash software” remains trashy.