My company[1] has written 100's of 1000's of lines of Terraform code as part of a commercially maintained library of prod-grade Terraform modules. We've also used Terraform to setup 100+ teams on AWS with prod-grade infra, and I can confirm that Terraform works very well for robustly launching on AWS.
There's also a fast-growing ecosystem around Terraform: lots of open source modules, automated testing frameworks, and a growing number of tooling solutions. In the early years of Terraform, bugs and stability were major issues. With 0.12, the maturity factor is becoming very compelling.
On a separate note, I'm surprised the author endorses plain old EC2 over Docker. I get the point of "choose boring tech," but it seems like launching your app on EC2 requires a whole bunch of rework around automation that's already done for you in ECS, EKS, or dare I say even Elastic Beanstalk + Docker.