Ignorance? I am coder with specilization on C#, Python and JavaScript, I can check for myself. Majority of people can't. And it's strange to expect them to do it, because it's the same to as to expect everybody being good at medicine, law, or beign able to draw and sing perfectly. The amount of knowledge that humanity help is way too big for everyone to be able to do everything, which leads to the existence of specialization. Well, even among IT not everyone is able to read others people code fast as well as there is people who use programming language wastly different syntax (mostly among serious sciencist) who maybe never worked with Git or decompiled .exe ever, are they also ignorant?
And there is plenty of cases of Open Source projects being compromised, sometimes very popular ones.