"mean to afk but we do also live a life that have to attend and have no other choice but to afk"
this is why the leaverbuster is set "high"
it is meant to deter you from leaving
if it was only 5 mins it would deter no one
case in point
the current system goes
5 10 20
Think of it this way
you're now invested into a game as you've waited 20 mins to even queue for one
now you're given an incentives to finish each game
Why 20 mins should be increased
you leave a game at 20 min mark
9 other people continue playing the game until the 40 min mark
you've now wasted 180 mins of other peoples time by you leaving
you've made the game irrelevant as you left
there is no honor in winning a 5v4
so 5 games at 20 mins is 100 mins
where as in 1 game you wasted 180 mins of other players times
If anything you've gotten off easy