There are two cases that we're addressing: 1. A developer writes an end-user application, but doesn't want to free their software. Clearly, this person isn't g

There are two cases that we're addressing: 1. A developer writes an end-user application, but doesn't want to free their software. Clearly, this person isn't going to use GPL libraries. 2. A developer modifies an end-user application licensed under the GPL. If a developer makes a modification and then distributes that modification, then clearly it was of use to someone outside of that developer. The GPL guarantees that every person who uses that modified software gets the source. But why is it good for an infrastructure product to be free, where it's bad for the end-user product? Or, is this as simple as the fact that most free infrastructural products don't require the end-user product to be free. So, it's "appropriate and beneficial" for them to be free. But, most free libraries do require the end-user product to be free, so it's bad for the developer who may or may not want to make their product free. If I've accurately summarized, then at what point where does that "appropriate and beneficial" aspect disappear?