Getting support and getting a whole new OS are two different things.
I buy a computer with windows 7, I don't get free upgrades to all subsequent versions.
But, yeah, I expect bug fixes. Everything beyond that is an entitlement mindset.
Not the same thing at all. The manufacturers have set the precedent many, many times over that they will upgrade the devices when android versions upgrade.
As for your comparison to MS Windows? Puhleease. Windows is a proprietary, pay for ownership and use, operating system. Android is not.
I completely agree with you on the don't buy it for what you hope the manufacturer will do with it - that just sets you up for disappointment. But I would expect LG to upgrade to KitKat (but haven't seen anything in KitKat I can't live without. If I did, it would be a Nexus for me.