I don't think R4tch3 was trying to self-advertise so much as just relating his personal experience of feeling more terrified at the game and pointing out those few moments
And really, while playing, it doesn't matter if someone is in chat with others or not. Pretty much everyone gets scared at the game haha!
I don't see what it's taking away from the experience, simply that you can enhance it by having fun with your friends while playing and laugh off some scares and move on. Just look at people's faces and videos where they have others with them, they still get just as scared and enjoy the game.
But this is getting a little off topic since this is about Day9's stream. So getting back on track, I saw a little of it, the guy is cool. Unfortunately I didn't get to catch any of him being scared or anything xD But I think he said it was like his 2nd or more playthrough of Amnesia (I could be wrong tho)! Honestly, I think the first time playing is the best to show, the umm "victim" never knows what to expect ya' know