It's like grade inflation. You can never give out an F (Mr. Admissions officer, are you so bad at your job that you would admit such an unqualified student?), so a Gentleman's C is handed around. In Amazon's case, it's a gentleman's B+ (green, with an info icon).

A: fine A-: problems B+: servers are on fire

I really like Amazon as a company, use a lot of their services, but this is dishonest.