Just a thought from a simple user - a closed license also means that the moment the author moves on to other things, or focuses on other parts of his life, the vision he so much desired to protect with a restrictive license also dies. I cannot express how indebted I am to the modders for expanding KSP to make, out of a decent thing, a great one. I share very little back, but possibly a tiny bit of feedback, and mostly silent appreciation. At the same time, a closed license acts as a reminder that the mod it contains is not shared, it is lent. And that's perfectly fine, I am not entitled to anything. But the distinction is worth making. For us users, getting over-reliant on mods that are lent is a road to disappointment and resentment. It shouldn't, but that's human nature. I sometimes do minor part tweaks for my own convenience - extremely simple changes that are within my grasp, cloning parts and retexturing, adding other modules to .cfg. Extremely derivative stuff for my own use. The thing is, even if suddenly something were worth sharing back, a closed license would provide a barrier to entry that I would probably not seek to overcome. Wikipedia kinda trundles on after nearly a decade and a half because the barrier to entry for contributing and expanding on other people's work is extremely low (and it also comes with its own share of problems). All closed license alternatives haven't ever thrived. TLDR: mod authors owe us nothing. However, if the prospect of becoming the giant on whose shoulders others are standing is appealing, I urge those of you modders who are thinking of restricting your licenses further, in part because of this thread, to reconsider. There will always be a few obnoxious types around who will tend to ruin everyone else's experience, but just because they PM you won't make them less obnoxious, only, perhaps, more courteous until the moment you tell them no.