That's absurd. It's hypocritical to describe best practices as best practices because you haven't perfectly implemented them? Either they're best practice or they aren't. The customers have the option of risking non-redundancy also, you know.
Hey! Pay us more money so when us-east-1 goes down you're not down (actually you'll still go down because us-east-1 is a single point of failure even for our other regions).