[linguae]

I concur; I believe selling software components is a difficult business model for the reasons that you mentioned. This may have contributed to Steve Jobs' decision to cancel OpenDoc in 1997: Apple needed the support of its existing base of software vendors, especially Microsoft and Adobe, in order for the Mac to survive, and OpenDoc, which was designed with the express purpose of challenging the types of monolithic, large applications that Microsoft and Adobe developed, was not going to win the support of Microsoft and Adobe. Even when it came to the question of whether Microsoft Office and Adobe Photoshop would be ported to NeXT's APIs (later named Cocoa), both Microsoft and Adobe balked, which forced Apple to develop the Carbon API to make it easier for software developers to port programs written for the classic Mac OS. If Microsoft and Adobe balked at having to use Cocoa, imagine the howls that would have came from a demand to port their software to OpenDoc.

However, I believe that component-based software is a natural fit in the FOSS community. One of my favorite Hacker News comments of all time is https://news.ycombinator.com/item?id=13573373, where the author makes the case for why component-based software would have been a better fit for the Linux desktop than the standard approach of trying to build a FOSS replica of large, commercial platforms.