Obviously they could have a consensual and transparent updating mechanism. This was not some sort of oversight.
Google's software is a cascade of lies and deceptions.
Think about this: when you start to tamper with Keystone agent, it never says anything to you, it just silently reinstalls itself somewhere else like spyware.
It will keep asking over and over for root access, without explaining why. They make it seem like your installation is incomplete without root access, but that is a lie. It will function fine running out of ~/Library/ as /Library. But there is no way to make it stop asking.
Google Earth, Google Drive, or many other Google products will re-install Keystone agent.
If I try deleting it, then that means I probably want it gone. They should prompt me to repair it or leave it alone.
You would think that Google would want to show off their updater. Even just a growl notification that an update has occurred.
But it makes sense why they don't want users thinking about it. If they were more transparent, they would say:
We've installed this software that will monitor your filesystem and make irreversible changes whenever we feel like it. Sometimes we will break things, but most of the time we won't and if we do break something, we will fix it. It is possible to disable, but you will have to search for it, because you will never discover it yourself. Oh, we could just have a checkbox in Preferences, but we want to make you work for it. And all you are doing is requesting that we stop updating, but we'll still be running.