What's up with these videos on youtube?

So I live in nj, and we have snow (finally its melting) on the ground, so im out of the game for the time being. I've been going over earlier finds , watching videos, and reading articles to pass the time and learn whatever I can. But seriously....what is up with these older guys posting videos of rocks that look straight out of my landscaping river rock? They sound so confident and like they really know what they are talking about. And most of the comments sound like people are eating it right up. I've seem so many of them....what is up with that? Is it a joke, or serious?