Access tokens are a 'manageable' risk and AWS provides tools to enforce best practices where necessary.
Locating and regularly patching security vulnerabilities across thousands of components in a fully-featured monolithic operating system isn't. It's a potential disaster waiting to happen.
You don't need...
...a huge bundle of drivers when the OS will always run on a VM.
...extensive filesystem support when everything will be either transient or run directly from memory.
...multiple users when only one is required.
...OS-level sandboxing (ie kernel/user-space) when the VM already provides sandboxing.
...native POSIX tools when 'safe' alternatives can be run from the VM.
Despite the best intentions of developers and admins alike, the current approach to security is not working. Despite my own vigilance, I have personally had my sensitive information leaked by two separate multi-billion dollar organizations in the past year.
It's a simple fact that every feature added, increases the attack surface of the entire system. All I'm suggesting, is that it's not a bad idea to start looking to the alternatives that are becoming available.