Speaking personally, I didn't donate out of some sense of duty to the abstract concept of open source, I donated because I have a vested interest in seeing Cloj

Speaking personally, I didn't donate out of some sense of duty to the abstract concept of open source, I donated because I have a vested interest in seeing Clojure succeed. If it reaches prominence as a language, that has a real, long-term impact on my career satisfaction. There isn't much open source software which fits that description.