Sure! The idea is that each proprietary project is wasting effort implementing their own clones of everyone else's software. To use your example, Google, Microsoft, Yahoo, Yandex etc etc are all developing their own search engines. Instead they could all be contributing to one search engine to push the state of search engine software forward, instead of all spinning their wheels re-doing what everyone else is doing. How many devs are employed doing what someone else in some other company has already done? That's the broken window: someone else has already done the work, but it must be wastefully re-done because of the license. There's a lot of room for profit in all that extra waste.