Why no mastery/rune changes in Game loading screen?

When I load into a game, I expect for everyone to give it their all and have some fun. I expect for my team to come prepared with the right runes and masteries... But after loading in or at the LAST SECOND where you STILL cannot do a quick swap, you go in with ap on an ADC. Why rito, why is there no extra time for changing runes and masteries? It has no effect on the game before it begins, meaning you could create another menu to "quickswitch" your runes & masteries. I think we've all been there, where we were just too busy making sure everyone wasn't trolling or simply being taken away from the game for a moment... that we forgot to change our runes and masteries. Rito, we need more time... I'm not a techno genius but i do know theres no negative to this idea really.