Which aren't from Google, meaning it can be trusted as much as any other OEM.

you could build CM or AOSP from source if you want

And void the warranty of a device in the process? No, thanks.

Do you still have a working warranty for your Nexus 4?

Nexus 4 isn't the only one that suffers from lack of support.

but thats what this comment thread is about.

Anecdotally: I have had a smartphone hardware fault repaired under warranty, despite having an unlocked bootloader and a custom ROM installed.