I'm not honestly sure that Nepo's ...b5 move was 100% blunder, and it makes me wonder how much of it was the result of Nepo lashing out in frustration after being pushed to passively defend for a number of moves after Carlsen found a great way to play against his ...h5 novelty. Nepo might have kind of seen it at the edges of his awareness, but may have simply refused to consider the consequences, as he got so fed up defending such a passive position and lashed out, consequences be damned. Maybe he didn't want to even consider how passive his position would end up being after ...b5
One thing is certain: Carlsen managed to massively frustrate him, and it was Carlsen who sacrificed a pawn in game 1 in his own "Magnus Attack" against Ruy Lopez. Yet Carlsen, seemed to have gotten away with his pawn sacrificies in a few games, so why not Nepo?
"I think people who are pretending to be surprised by mistakes made at high levels of competition are very new to how high level competition works. It's almost as if they have never seen a high level competition before"
The people screaming the loudest have never been and never will be involved is any high level of competition. They are low level people