This can be abused in many ways.
F.e.
-When someone picks Teemo / Heimdinger because he is a Teemo / Heimdinger main, the team might look or frown upon the fact they picked those champions. They might choose to dodge because they don't want to play with these type of champions.
-When High Elo Diamond 1 - Master Tier whom frequently face eachother plays with someone who was deemed unskilled and bad the previous game they played, they choose to dodge to avoid playing with the unskilled player.
-The enemy team has an extremely better teamcomp with overpowered champions, such as Gangplank and Mordekaiser, so they vote dodge to avoid the hard gameplay they must endure.
There are many flaws in having such option in champ select.