You are right with many points: Chromebooks are indeed designed to be dumb terminals to Google's services. But on the other hand they have an amazing sandboxing system for all OS components and take security seriously. Compare this to most Linux distros that allow basically every local app full access to the user's account.

I wouldn't use Chrome OS as it is right now. But a degoogled version of it, maybe with some better local only support, or at least support to use a different cloud than Google's cloud, say some NAS in my home, and it would be a really nice device.

Because Chrome runs from read-only media on the Chromebook in Guest Mode, some Chrome settings (chrome://settings) are not changeable. For example, one cannot globally disable Javascript or cookies globally. It is possible to disable these "features" only using Developer Tools and therefore only on a per tab basis. Settings are lost when the tab is closed. Similarly, any changed settings in Chrome (through chrome://settings) are lost on reboot. As such, a computer user who dligently entered per site settings for privacy and security would lose all her settings every time she reboots the Chromebook.

Needless to say Chrome defaults favour Google and Google's advertiser customers. Making it impossible^1 for Chromebook users in Guest Mode to save and import privacy and security settings is a dark pattern.

1. Google employees will proclaim this is incorrect. All the computer user has to do is "log in" to Google in order to save her settings. Once logged in, Google can collect more data about the computer user. However non-employees of the corporation may not wish to "log in". Google employees assume that all computer users should trust Google, like they themselves do. Given that Google is collecting as much data about them as the law will allow, and then some, this is a curious assumption indeed.

Revised comment:

It is possible to create customised UNIX-like OS with custom kernels, read-only filesystems (mounted images), writable directories mounted as tmpfs, and encrypted disks, booting from removable USB. Some call this "diskless". There are some drawbacks from using USB media such as lack of a good randomness source on boot but there are many advantages. Kernels and filesystems are just single files on the USB media and can be easily switched/updated. The system stays "clean". It is "like new" on every reboot. I was doing this with a netbook long before the so-called "Chromebook" came along.

The problem with Chromebooks is that they are designed to try to get people to "log in" to Google, to use Google-controlled websites, to use online software controlled by Google and to use online storage managed by Google rather than local storage managed by the computer user. The later may be more convenient but it also poses higher risk for computer users while at the same conferring commercial value to Google. The company wants computer users to use its websites and software in lieu of offline storage and offline software.

Chromebooks in Guest Mode have an array of Google-authored daemons running the the background from read-only media. There is no way to control or disable them. You cannot even change the options passed to Chrome, e.g., to disable "Origin Trials". With these Google programs always running in the background, it means you do not have ultimate control over the computer, Google does.

Another annoying thing is that ChromeOS, as well as Chrome, is a work in progress. It is constantly changing and the computer user is treated as a beta tester. For example, something like Bluetooth may be working fine and then suddenly there is an "automatic update" that breaks it. Then the computer user must wait for Google to fix it. There is no way to go back to the previous working version while waiting for the fix.

One has to consider the "security" implications of an OS that steers people to use Chrome, online storage and genrally to remain online as much as possible. Google programs are constantly running on Chromebooks and probing for internet access. As such, ChromeOS is an OS that encourages risk-taking, i.e., giving more data to Google, including storing more user data online. Chromebooks are not designed to be offline by default. ChromeOS forces users to run Chrome. Google is always trying to collect more data about computer users.

I always make diskless systems to be offline by default. I use offline storage. There is no phoning home for "updates" to an advertising company. I decide when and if I want to "update" the kernel or userland.

http://nakedsecurity.sophos.com/2017/11/22/chromebook-exploi...