They don't get force-rebooted that often, I have EC2 instances that have been up for over 365 days with no issues.

Setting up instances, managing updates, adding IAM perms is orders of magnitude faster/easier than dealing with rack-and-stack data centers.

Full downtime isn't that frequent, either. The Kinesis outage on Wednesday didn't affect any of our USE1 functionality, with the exception of maybe Cloudfront propagation.