The cynical side of me thinks that when carriers say "we're only blocking the updates for your own good, we want to know they work" they really mean "if we block your updates for long enough and you want new features then you'll upgrade your phone faster".  Most of their business model is trying to figure out how to double charge you for what you already pay for and coming up with fees to make money off of doing nothing more than you were yesterday. 

It's like paying a water bill, but having someone say "oh, well, you decided to drink the water, you'll have to pay a fee for that on top of the fee for the water itself.  And if you want to shower with it, that's an extra fee... and if you want it hot... you'll have to pay the regulatory hot water fee... and don't even think about sharing it, we'll double your cost for that.. that water is for you and you only.. if you want to water your plants with it then you're abusing the system... each plant watered will have it's own fee associated with it.  Further, we will now charge you for the speed at which the water comes out of your faucet... if you want full capacity that will be an extra $10 for yourself and $5 additional for each person enjoy full capacity water usage".

The sad thing is, there is little competition and since they all employ the same shoddy practices you can't get away from it if you want to use a cell phone which is a requirement for most of us in our work.