When Josh proposed the idea to me I asked a few people about their experiences with their banks. One of my friends told me how she had accidentally double-booked an airline ticket. This overdrew her account and--since she uses her debit card for everything--she started incurring overdraft fees on everything she purchased. She ran up several hundred dollars of overdraft fees before she even realized she was overdrafted. When she called Bank of America to explain, she was given the runaround. They eventually refunded half the fees (their standard offer) but refused to refund the rest without her jumping through hoops.
My friend is a single mom with two kids and a full-time job. She did not have time to constantly monitor her bank, nor the time to jump through the bank's hoops. Paying the fees caused her significant hardship.
The big banks in this country make their living by preying on those least able to protect themselves. They are evil. Again, I can't speak for the other investors, but I am not interested in selling out to a big bank. Success for me is either beating the other banks or forcing them to compete on Simple's terms: by treating their customers like people.