This may have something to do with a difference in approach from the two banks. Lately Amex has been lowering their overall credit standards compared to what they were 5-10 years ago. People are getting accepted with quite frankly, mediocre scores whereas years ago they wouldn't have even been considered. This might be Amex trying to stave off the DoJ, but also because they feel the need to increase their marketshare. BofA on the other hand is reducing it's risk anywhere it can. They are closing accounts that appear questionable or are not profitable enough. They've been in a bad spot since their acquisition of countrywide financial, so they've been trying to get rid of anyone they deem as potentially risky.
EX 798, EQ 789, TU 784
American Express Platinum (NPSL) || Bank of America Privileges with Travel Rewards Visa Signature - $23,200 CL
Barclays American Airlines Aviator Red World Elite Mastercard - $20,000 CL || Chase IHG Rewards World Mastercard - $25,000 CL
Chase Sapphire Preferred Visa Signature - $12,700 CL || Chase United MileagePlus Club World Elite MasterCard - $26,500 CL
Citibank Hilton Reserve Visa Signature - $20,000 CL || J.P. Morgan Ritz Carlton Visa Signature - $23,500 CL