There's also the possibility of trade secrets being involved. An example hypothetical: Maybe Qualcomm has tons of lab data showing signal performance and integr

There's also the possibility of trade secrets being involved. An example hypothetical: Maybe Qualcomm has tons of lab data showing signal performance and integrity for any given channel, band, power level, general environment (urban, suburban, rural), device position, device altitude, etc. You might want to use that data, and algorithms derived from it, to improve your device's battery life. That data obviously cannot be patented, and while the lab data would be copyrighted and not part of the finished product, Qualcomm would understandably be mighty particular about any open-source code implementing the conclusions.