Re: "unable to implement an automatic update for Android"
Not defending Google, in fact I agree with the sentiment at least, but the fact is there is no such thing as one "Android OS" that Google can deploy to millions of handsets. Instead there are countless proprietary smartphone operating systems based on Android, deployed by various manufacturers to devices that Google has no access rights to, at least not for the purpose of updating the OS.
And if Google could somehow update the OS remotely, it simply wouldn't be the same custom OS as provided by the vendor, it'd be vanilla Android, missing all the proprietary bits necessary to keep the vendor's proprietary UI and shovelware running, missing the vendor's proprietary drivers necessary to keep the hardware working, and would thus also invalidate your warranty, which is with the vendor, not Google.
This is the problem with OEM arrangements in general, not just with Android in particular, and is a problem that Apple avoids by being both the OS developer and the hardware vendor.
Of course another way to avoid this problem would be to abolish all the proprietary junk in both the hardware and OS, and have an open hardware, open specification, open source solution where everyone could apply daily, incremental updates to every part of the system, including apps and core OS components, but then companies like Samsung would whine about losing their "competitive advantage", as we'd all be able to construct our own smartphones from kits in Maplin.
Actually an even more fundamental reason for all that proprietary junk in smartphones is that the FCC/CEPT/Ofcom mandate that a lot of it must be a black box, incapable of being fiddled with by consumers, but that's another story.