|Because the point used to be that one should be able to see and hear the show. To be fair, our audience design (the old Broadway houses) was adapted from 18th Century models. The stage used by actors used to be in FRONT of the proscenium =- the box seats flanked the stage - so the actors were sharing the same space as the audience - the best option for acoustics. Behind the proscenium was scenery and special effects - which were always focused dead center where everyone could see. But all of that was slowly lost, the stage moved back behind the proscenium, and the row after row of box seats on the walls of theatres disappeared, as one could no longer view the actors from those seats. If one wants to blame any one for sight line issues in shows, leave directors and designers alone. It's the producer's fault. They hire every one. They approve everything. They are the ones that ultimately decide that from your seat you cant see the entire show. They just dont care you're going to pay $150 anyway. Being a producer means you can't pass the buck to anyone. "Oh, I hire the best creatives and then just trust them." No actual producer worthy of the name would every say that. On Broadway, today, sadly, many do. I've heard them up close and personal.