Part of it is that us old greybeards have been around long enough to see what works and what doesn't. IT is more "cult"ish than most industries. There are long-held destructive beliefs that cause projects to fail or other problems. For example... RESTful APIs. If you're building a single-page web app then it's probably going to work really well for you. If you're replacing a B2B api that "does something", you're gonna have a bad time.