It's hard to justify not putting a mandatory arbitration clause into a contract, even if it is unethical. It's an incredible boon for companies and most users don't appreciate what they're losing.
1. Arbitration is going to potentially save hundreds of thousands of dollars down the line if there's a legal issue.
2. Arbitration incredibly favors the company over the customer.
3. Most customers don't understand the value of their right to civil action.
So while an arbitration clause is, in my mind, equivalent to telling your customers you don't actually care about being reliable, many companies are putting them into place just because they can.
#2 is true in most instances, but in order to find out you have to actually go through the entire arbitration and pay your lawyers' bills
#3 is very true, but that only adds to the idea that it's unethical.
Companies put them in because the corporate defense bar thinks this is the new hotness -- and few of those folks have ever actually litigated any of these clauses.