Using GPL forces all programs using the library to also be GPL that is the reason why a GPL library can't be included in AROS but a LGPL one can.
This can be tricky to understand. Are you using a GPL library here, and thus taking on the GPL, or is the GPL library using something else from the OS or other binary-only proprietary distribution? You can't write a GPL thing that makes MS Windows become a GPL OS just because some GPL thing used an OS function call...
Look at ReactOS, it's a GPL reimplementation of old MS Windows API and intends to be binary compatible with drivers and apps etc. written/compiled for MS Windows. I don't believe that a user trying to run some proprietary app on ReactOS makes that app become GPL. You can also have proprietary software on Linux.
So, where are the GPL lines here, and which direction are the calls going in, how do all pieces fit togehter, and when and under what conditions did which binary get compiled? Are there legacy proprietary things making use of other legacy proprietary things, and you are trying to fit in an open-source layer in between them, or replacing them? Legacy proprietary things can remain proprietary, as they were not written for or linked with a GPL thing, they were designed to a proprietary companion. Pulling that proprietary companion piece away and replacing it without knowledge of the original proprietary author or toolset does not force GPL onto the other proprietary thing that isn't aware its now making use of a GPL companion thing. While some see GPL as a cancer, it doesn't grow quite that way...
You can also look at using LGPL middleman tricks, such as how some proprietary drivers work with Linux kernel. That gets further into grey area, but the above is less grey than that.
