Well, fortunately for a lot of things it's possible to find out what's true or not. Ignorance can be cured. Suppression and denial, not so easy.

I come from an odd culture of technogeeks. Arguments weren't supposed to be about deciding who was right, but what the facts were. The imperative over everything is always, "does it WORK?" Back in the day when HP calculators were expensive luxuries, I actually saw a couple of guys literally slap leather during an argument as they pulled their calculators out of the little belt "holsters" they carried them in. (I still have my old HP35, and it works.)

But of course engineers are human like anyone else, and will cling to an idea longer than they should, sometimes long after the data is staring them down. The worst thing a technological designer can do, and probably the most common, is to fall in love with a concept. Pretty soon they're not fixing the flaws, but making excuses for them. A lot of businesses have foundered on this.