Developers and engineers in general develop an ego with time. They take pride in their work and are very protective of it. They also relish the petty mistakes that others make and scoff at them - 'pfft I could have used X instead of Y to do Z. Who uses Y anymore !?'.

For example, you can find this behavior when someone posts something about problem X and there is a minor grammatical mistake or an opinion that is expressed in the post that is unconventional. The comments section will zero in on that and miss the big picture.