Arbitration is usually a better, less expensive way to settle a matter, but ultimately it's less expensive for the company. Many of the cell companies have this written into their cellular contracts, and it has the effect of chopping you off at the knees if you have a problem.
Arbitration gives you "inferior bargaining power."
You're agreeing to step into a boxing ring with a bigger player, and give up a lot of ground and rights. There are advantages and disadvantages.
Arbitration is different than mediation in which an intermediary seeks to help both sides come to an agreement.