You mean, why do people want to see the performance? Or why do people rent broken, blurry, old-fashioned binoculars that probably carry more germs than the door handle in the men’s bathroom at Kievsky train station?
So they can get out of theater quickly after the performance.
You see, one of the perks of renting those binoculars of dubious usability is that you get to cut in line in front of absolutely everyone, hand them in, and get your coat. Presumably this was begun as an incentive to rent them. It still works. It will be the best 100 rubles you have ever spent.
Another trick to get through the coat-check line quickly: Find the row of coats and attendant closest to the exit from the theater. The lines tend to be slightly shorter — people tend to go to the center of the hall — and it’s quicker to leave after you get your coat.
While it’s considered to be in poor taste to get up and out before the last act of over, if you do need to rush off, abandon your seat after the last intermission and stand in the back of the balcony. That way you can leave without being rude to either the performers or your fellow audience members.