How do you not blame Heroku? You are paying them a good chunk of money to handle not only hosting, but failover strategies, multiple locations, etc. If you have to worry about any of those things they aren't doing their job.
That's like if you chose MySQL as the database, and then when an update had a huge bug that broke your site, you say "totally my fault that I don't have a version of the site that uses PostgreSQL."
To clarify part of this, Heroku doesn't have the same position as (say) a router manufacturer because they are offering an all-in-one 'platform'. And unlike MySQL, they are charging you a decent rate for using it.
That's like if you chose MySQL as the database, and then when an update had a huge bug that broke your site, you say "totally my fault that I don't have a version of the site that uses PostgreSQL."