Thanks.
That is some decent scathe. I don’t know Zach, nor do I know how hard (or not) he worked. Nor do I know if those are good numbers for him; I mean he could possibly have a handicap or pre-existing injuries, weird limb lengths, or hyperalgesia for example. But it does potentially outline two components of the formula that are often forgotten: consistency and consistent of hard effort. Those two components cannot be bought or ingested. Being consistent is important - that in itself seems to be the hardest thing for most people to implement. Then, in addition to that, one can be consistent yet never push themselves. So most people who end up being consistent, don’t actually consistently push themselves, and just end up in a lifelong period of stagnation - at least it’s better than nothing. For the minority of trainees, who are both consistent and consistently push themselves, that’s where we see the real transformations IMHO. In addition, gains are made almost regardless of the effectiveness of the training system - though optimal gains will be made on a more effective training system, gains will be made nonetheless.
I would imagine that most coaches, Ph.d exercise science folks, B.S/M.S exercise science folks etc fall into the majority of trainees, lacking one or both of those components. To make things worse for “intelligent people”, they often suffocate themselves in over analysis. They are often in search of “the perfect program”, “the perfect exercise”, “the perfect supplement”, “the perfect coach”, “the perfect shoe”, “the perfect aerodynamic running short”, “the perfect nutrient timing”. Other than PED’s, it’s mostly just an excuse not to bite down on the mundane and perfect it. The monotony of “true” performance training can be a painful grind. Most everyone looking to “mix it up” and “have more fun”, are really just subconsciously implementing speed bumps in order to slow themselves down. People love to get stuck in the “newbie gains” phase, because it’s not a mental grind (war) yet. Once you get to the point where adding 1" to your jump may take 12 months, or 10 lb. on your squat 6 months, or 5 seconds off your 5k 6 months, with consistent hard effort, one is now in the real battle. From what i’ve experience and witnessed, human minds & bodies will do everything possible to avoid this stage & convince you to take your foot off the gas pedal.
It’s definitely possible to be able to give good advice, write a good training program, offer sound nutrition advice, even though you haven’t done anything impressive yourself. I mean, nearly the entire s&c community falls into this category. Unfortunately, lots of “failed athletes” turn towards coaching - unfortunate that they were failed athletes, not that they turned to coaching. If we were to all of a sudden just turn to elite athletes to give us advice, we’d get alot of really shitty advice: just use jump soles and stretch! However, I think it’s MUCH HARDER to help someone who was never particularly athletically impressive and/or “physically gifted”, but always dreamed of transforming into “something else”, transform. So that goes back to the post of yours you quoted - alot of people coming to online forums are just “normal people who want to transform into freaks” (athletically, physique, etc). I mean it’s not like we see tons of professional & collegiate athletes on these forums, it’s mostly dedicated “enthusiasts”. So definitely agree there, lead by example. FWIW, we can also learn alot by “fail by example”. 
Regarding the idea of “finally putting the knowledge I paid for to use”, IMHO that could be a red flag. Acquiring knowledge is very important, it forms the base upon which we build experience. That quote itself implies a major lack of experience though.
Edit: As far as elite athletes go, it’s hard to find ones who lack those components. So many different training systems, coaches with different ideologies, nutrition plans, body types, leverages, yet so many similar performances at the elite level. It really speaks alot for how consistent & how hard they push themselves, IMHO. It’s easy to find people “shitting” on elite athletes and attributing most of their success to “genetics”, but to be successful on the elite level, it’s hard to find elite athletes who aren’t consistently driven for literally decades. IMHO, it really speaks highly of being consistent & the ability to push yourself.
/ 2 cents.
peace