To me it seems to be largely individual, but it might also be boosted by some factors inside our industry. I think it all boils down to ego and us identifying ourselves with our own ideas and opinions, almost everyone does that to some extent. And when you see it like "your idea or opinion == YOU" every attack on the idea/opinion becomes attack on you personally. And then all of your insecurities and ego come into play.
I think it's very important to understand that ideas die or transform while opinions change. Both are to be and should be questioned if we want to grow both personally and as a society because many minds can weed out bad ideas and unfounded opinions very quickly. To do that effectively we need to be able to see our ideas and opinions as some kind of products we produced at a certain point in time with limited experience, skills etc. up to that point in time. They may stick with us to the very end, but most will get replaced with better versions as we grow with experience, skills, find new ways etc.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.