Earlier quoted context omitted.
Gifts do not confer obligation. Copying deprives the original party of nothing. Absolutely nothing about free software requires or even implies any responsibility to “give back”. This idea that anyone making money with free software somehow owes the original authors anything (or “should” donate a portion of their profits) is ridiculous. If the authors wanted money for their software, they would have sold it instead o…
There really is no prize for being technically correct on this one. Someone built this and is letting you have it. For free. There is no legal obligation or law of the universe here, sure, but if you're in the top 1% of benefactors of this pro bono work, you have the opportunity to do some good and make sure that others, like you, get the chance to benefit from this free work in the future. There is a pretty straight…
Giving a fake gift that comes with unspoken strings attached (and “keeping score” in your head) is the passive-aggressive, immoral act. If reciprocity is expected, it is definitionally not a gift.
Releasing software under a free software license is a choice to give a gift to the world. If the author wanted moral obligation strings attached, the license would say that.