If you want a medical opinion about a serous health problem, you go to a doctor and not to the guy who takes your money at the auto parts store. And if you want tax advice, I hope you go to an accountant rather than the checker at the supermarket.
Not all opinions are equal. The opinion of someone with applicable training and experience is worth more than the opinion of someone with none. The opinion of my doctor regarding my health is more worthy of attention than that of my mechanic; just as the opinion of my mechanic about my car deserves more attention than that of my doctor. If that weren't the case, I'd need a new doctor and mechanic.
You bring up a good point and I'd like to take it a bit further. How valuable is the opinion of someone who's actually done nothing (has zero personal experience), but received training from someone who actually had the experience?
If I went to a doctor and he told me all about pancreatic cancer, am I now qualified to go start diagnosing people?
Do you really know anything if all you know is what someone else told you (who may not have actually done it himself...and in fact, may have been told it by someone else, just like he is telling you)?
I've seen quite a few "trainers" and "experts" who can regurgitate information, but have ZERO actual experience doing what they are teaching. Do they really know anything? Would you really know anything since your training came from someone who doesn't really know
what they're teaching?
Who's the real expert? The guy who's had all the "training" but has no actual experience, or an old farmer/construction worker/whatever who's had no formal training, but has actually done the stuff?
***The "you" in this post isn't YOU. Just the generalized "you", as in we.***