Well like I said, you could disagree whether they are good reasons but to me they are good reasons.
> An analog radio can do exactly that.
An analogue radio can do anything that an internet connection or digital radio does, but it's sort of redundant to reimplement all the functionality that modern IP gives you just because you don't like the internet.
In particular, my alarm doesn't have any programmable analogue radio, so I'd presumably need some sort of module to interface with my alarm or to change my alarm for one that supports the analogue radio that the car alarm uses. With the internet-based approach, I have a little script that reads my car's API and triggers my home's alarm with its API.
I can also do things like sending me a push notification on my phone if something happens to my car when it's parked in a public car park.
Also, analogue radios aren't necessarily safe either. In most cases, digital technology has better encryption as it's easier to implement. In the UK, signal amplification attacks are becoming an increasingly common way to steal cars, which obviously wouldn't be possible using an internet-backhaul. Digital also tends to use less power and is less prone to interference.
> no software that actually controls the operation of a vehicle should be remotely accessible -- to anyone.
Remote disabling of cars in operation is obviously not good. However, MOST cars implement lockouts by having it so if you turn them off they can't be turned on again, which is a lot safer - and works more like an immobiliser which is a well proven technology. Both this and immobilisers sometimes have faults, but it's probably one of the least likely things to cause a fatal accident on a car.
> But why should something like that be linked to the driving/operation software?
Well I wasn't arguing strictly for linking to driving software, just reasons to connect a car to the internet. But I think the reason these systems have a connection to the operational software is to detect what's actually happened to the car - has the airbag gone off, what was the speed of the impact, what do the sensors say, etc. I don't believe there is any intent that they can control the car, but as soon as you link anything digitally there's always the possibility.
> That's the worst idea.
For most people, it's a great thing. I'm not sure there's ever been an attack caused by a remote update system in a car, but at least in computers, remote auto-update has been one of the best things for security and stability in the last few decades. There are a ton of theoretical issues with it, but in practice the benefits outweigh them.
Imagine your car's fly-by-wire software is discovered to have an unintentional acceleration bug. Remote updates means everyone's car is patched immediately. Traditional updates mean maybe if you bother taking it in for your annual service to an official dealer, it might get patched if they remember. You might be one of the 0.001% who would put it on a USB pen and patch it yourself or obey a recall, but almost nobody else would bother.