"this could definitely get ugly for companies that misbehave"

It doesn't just have to be companies that misbehave. If you don't like your competitor, maybe you'll sponsor that $250 per user to allow their userbase to throw arbitrations at them.

You can burn your competitor down at a ratio of at least 1:5 if you do something like this. If you take some fees for every case you win or that ends up settling, the ratio will be far better than 1:5

The arbitration system as it stands is a tool that allows anyone with enough money and intention to smite any company by pulling together unhappy users and paying arbitration fees for them.