Performers are VERY MUCH in control of the crowd. They literally have everyones full attention as well as A FUCKING MICROPHONE making them the ONE voice everyone can hear. I have been to multiple shows where the performer stopped the music to get people help or just generally say "Be safer". One time they literally forced around 10 thousand people to "take 10 steps back" before they would restart the show because people were getting smashed and NOT having fun up front.
True. Grateful dead used to play a simple drum beat, and Bobby would get everyone to step back on the beat. It's really cool when artists do that stuff, but it can't be relied on.
Your anger is justified, but maybe misplaced. Event security, planning, and safety all are to blame, and the people paid to do those jobs failed. I can only blame Travis if he knew how unsafe the conditions were and decided to continue regardless.