Well let's see. I've been playing online video games for over 20 years now, all the way back from Ultima Online, up through the modern day. I've played as the noob, and with the noobs. Seeing as I generally don't guild up, or if I do, I don't run with guild members regularly, and usually end up PUG'ing most runs, I would say that your hyperbole that no noob is fun loving (and all the other assumptions you made about them) aren't reflective of reality.
From my experience, the "pros" you mention, offering this "advice" are usually the more toxic, and initiate the toxicity. They have zero patience for someone who doesn't play to their standards, if you even dare to ask a question, they overreact and cuss you out in the process, and even overlook their own flaws. Because no pro is above fucking up, but the most common "pros" out there, like to deflect all blame onto the other players. They have zero fault in the team failure, it's ALL everyone else. "Learn to play you fucking scrub" "OMG why are you using that gear?!?! You fucking noob! Goddamn FTP shitbag!" "Learn the Meta or fuck off!" etc etc.
In fact, i would say that the more mythical creature, is not the "fun loving noob", because I have seen plenty of those myself, but the "fair and reasonable pro offering polite advice." Now while I have seen it myself, and am one of the people who actually doesn't mind taking time to explain something politely to someone, 95% of the time someone with more skill educates someone with (perceived) less skill, it's in a very hostile, toxic format. Because usually, by the time you realize someone isn't up to snuff, your party has wiped once. A bad pull, the crowd control didn't work properly, the DPS kept hitting the wrong target, the tank wasn't holding agro off the healer..the list is endless as to the event itself. But after that happens, it's WAY more likely to get someone to lash out in hostility, than a reasoned response.
So no, I don't agree with your theory that fun loving noobs don't exist, because they do. But what is directly opposed to them being a prolific kind of being, is their polar opposite...the Dicklord Veteran Player.