The context of what
@SergeConstantin74 was talking about is the overall number of NHL draftees from the Q decreasing. So it's about
who get drafted and who doesn't get drafted at all. Mesar/Kulich are too high profile for this context.
He gave an example of 2 fictitious players Jeff Smith (Oshawa) and Simon Poirier (Shawinigan).
Now to clear up a misunderstanding in this discussion: If a scout, any scout, think Simon Poirier is going to be a NHL player, the scout is going to push hard for his guy and Poirier will to be drafted. But that's not the type of prospect he was referring to here.
In any given draft roughly 50% of the draftees never play in the NHL, most of that bunch never even get a pro contract. So a lot are long shot, teams taking a flyer on players with low chances of success in hope they will figure it out in the next year or two and earn a pro contract.
Now if both Smith and Poirier are similar player in the crapshot-tier.
Teams are just more likely to pick Smith because they will have seen more of Oshawa than Shawinigan (scouting unbalance) and/or because one NHL Exec know Oshawa's coach personally because he used to work in that league or he played with the guy, which is a lot less likely to be the case for Shawinigan's coach. Both junior coach are vouching for their player and NHL teams are just more likely to put more weight on the words of someone they know personally than someone they don't (networking).
They go with what they know and if it's scaled up to an entire draft, more "Poirier" will go undrafted than "Smith".
Most of the "Smith" will never play in the NHL and most of the "Poirier" would have failed if they had been drafted but it wasn't about "who make it", it was about the number of draftees from the Q.