The trouble with doing stuff while in a queue

Sometimes while I'm in a queue and waiting to join a game, I'll work on a rune or mastery page, or browse the shop... something to pass the time. And then the prompt pops up, and I click accept, and someone else declines or doesn't answer, so the game doesn't happen. Then, instead of returning to whatever I was working on, I'm kicked out to the landing / home page again. Every time. I realize this isn't a bug, and that it's designed this way for some reason. But I don't understand why. Why make us stop working on stuff just because someone wasn't ready for their match?