If you were going to AFK a round, why not just leave and then find a different server when you're ready to play again?
It's unfair to others who DO want to play, as you're still taking up a slot on the server even though you're sitting out.
You may have trouble getting back into the same server, but then again there are a lot of others to choose from.
If being unable to join games is too frustrating, then either play during times which are less popular, such as weekdays or early morning/late night.
Otherwise save up and become a donator.