One of the reasons is that in programming there is a lot of domain-specific information which you need to know. Many times there are different but roughly equivalent ways of doing things. Which one you choose doesn't really matter. Not having to deal with both at once, does. A lot. In other words expertise is fragile. Guru-hood is easily lost from apparently small changes in your working environment.

So before your next flame war, stop and think about what you are arguing about. The odds are pretty good that it is one of these important irrelevancies. This is almost certainly true for most of the "religious wars" that you see.

Hiding that behind an attitude that you are, "Just pointing out the facts, Ma-am!" is disingenuous at best. You are being destructive. Before doing that give it careful thought. Why do you feel so strongly? Do you believe that the other person will find an immediate improvement in their life from taking your advice? Are you being a rigid asshole who refuses to change because you are scared to suddenly be incompetent in a new world?

Yes, there are things that matter. But most of the ones that matter to you personally are not based on anything more meaningful than the fact that they preserve your domain based expertise. (Which I assure you will largely be lost by changes in programming over the next 5 years.)