Part of what makes Random BG’s special is you don’t have the perfect team with the perfect number of players, with the perfect skills, with the perfect specs. You have really good players and really bad players, experienced and “the lost,” along with the geared and undergeared. This randomness is built into the match-Random Battleground.
For the most part (I know Alliance won’t agree) the enemy team has the same chance to have all the good and bad your team has. It’s then up to each team to overcome and win despite the obstacles such as two tanks telling poop jokes.
Probably the biggest reason Blizzard doesn’t allow Vote Kick is everyone is not allowed to Win in PVP but they are allowed to Play and learn.