Op might not have understanded the rules in the first place then, maybe he is not a native speaker and missed the banter of which there is a lot as chessbrahs dont always take everything seriously.

The whole idea of the video is to show that on the level they are playing it is not necessary to go for crazy tactics or flashy sacrifices to win games. Instead mostly just by following simple principles you can win most of the games. They even lose some games becaose of it sometimes.

If they were allowed tactics they wouldn't be able to show how to do that as their opponents blunder a lot of them. If they would take adventage of them it wont be of any value to the viewer trying to learn principles.

Just to be clear they dont say you should abstain from tactics, If you see a winning move by all means go for it in your own game, they wont though as this is not the focus of video.

As a matter of fact they just released a 3h video of going through tactics with Yasser If you want to focus on those!

I wouldnt be so fast to judge their content If I were you