Forget the wordy title, the idea is simple. Human beings tend to assume our personal way of doing something is the "better" way to do it. Other people feel the same way, and we can't all be right.
People who fly fish share a strong bond with one another worldwide, but that bond is thinner in some spots. Hardcore dry fly anglers turn their noses up at nymph rigs. Spey-swinging steelheaders tolerate nymph and plug drifters with something short of animosity. Tight-line nymphers and Euro-nymph enthusiasts both sneer a little when they see a thingamabobber rig bouncing along. Line color, casting style, clothing color, leader design. Whatever detail you can come up with, there will already be a camp on either side of the line.
Is it useful to think this way? My answer is both yes and no, within limits.
An angler who is a spey-swinging purist (not to pick on you lot) can develop exceptional skill as a swinger, because they can focus on development of that skill within a bounded context. Pushing distractions aside has a lot of value. But what if we imagine that same angler on a boat cruising the deep blue sea for Pacific sailfish, or on a windy flat somewhere near Belize? The spey-swinging skillset becomes much less useful. Similarly, expert sailfish fly anglers might have serious trouble fishing the trico hatch on Silver Creek, unless they've developed that specific skill.
There is a mental trap hiding behind ideas like "Czech nymphing is the best," or "swinging is better than drifting," or "dry fly fishing is the way of the truth and the light." I have no doubt that the best dry fly anglers would benefit from a few seasons of stalking bonefish. Salty flats-fishers could easily find themselves humbled by trout on the Henry's Fork. Showing up to a muskie fishing trip with your PMD box would be an embarrassing move.
Rejecting approaches you have not explored because you're pretty sure you know how to catch a fish is a big mistake. Be helpable and you will develop quickly, as an angler and a person. Learn how to recognize good advice and act on it.
Having a sense of your personal limits is invaluable. Don't get caught up in the idea that your pet approach is somehow superior to someone else's take on the same thing.
New understanding can be gained from accepting your own ignorance and inexperience when faced with an unfamiliar situation, rod in hand or not.