Okay, based on what I see in my feed, you really want to engage on this topic. I'll bite, but do my a favour first, okay? Take a deep breath. Relax. It's one video. It will not change the hobby. It will not offset D&D encounters or Pathfinder Society.
To the main point - I don't think the insinuation is that people are dumber now than they used to be. I believe that it is about asking as little as possible of a new player. As you said, the biggest thing is that you need players to game with. Sure, a good group can do their utmost to lift the burden of entry as little as possible. What I believe the gentleman here is saying is that you can select a system that does that for you. Because as I'm sure we're all aware, not every group is a good one for new players.
And sure, you might have a hard time getting players for a lesser known game. Hell, you will. I can attest to that. But the first game you play does not have to be what you spend the majority of your time in the hobby on. It should give you a taste and leave you wanting more. If you really want it, I gave it a goggle, and the first hit was it's page for sale on DriveThruRPG. So yeah, it's available out there. Yes, I know this sidesteps the stores. I like to support them, too, but I can't always.
I don't think that people branching out from D&D is bad for the hobby. The fact is, D&D isn't right for every gamer. I personally know many people who wouldn't even play roleplaying games any more if the only options were games like D&D. I do think that it can help to have companies capable of getting new players to join. They can advertise in ways that others can't. As for how profitable D&D and Pathfinder are right now, I don't know.
Regarding some other comments, sure, there might be players who can't or don't want to master a system (as system mastery if definitely a thing with games like D&D in many groups). You're right that not everyone places story first. Not everyone places the game first, either. Different is not wrong here. There's space for both.
Ultimately, I think the game to introduce a player with depends mostly on the player and what they're into. Think of it like a more fun version of a job interview. You want to show them what the hobby has to offer that they're interested in. And, where I agree with the gentlemen here - you want to make it as easy on them as possible to get involved.
D&D isn't the worst option, but it's not always the best either.