iMac fried by the macOS update

I doubt a change in software physically damaged your logic board.

Unfortunately, Apple has made its decision. Being out of warranty, repair costs are yours to pay; the Apple guy has no choice in the matter.

You did not purchase AppleCare, that was your choice. The update did not crash the machine, your machine suffered a hardware failure, you decide to self insure and now you want someone to blame. The responsibility was yours so you need to own that.

Sorry it happened to you but there is a lesson to be learned.

They also recommend you use the Mac for it's intended purpose. Are you going to blame Apple because using the Mac as it was designed to be used wore it out?

Recommendations do not cause physical failures. But, your opinions are your own and you're welcome to them.

Again, the update had NOTHING to do with the update. It sounds like you are located in Europe, please check the consumer laws for the country you reside it. It is possible it has a longer warranty based on local consumer laws.

No, we don't accept that. I agree that 2 years is pretty short. However, most macs last much longer than 2 years. But failures happen. That is why extended AppleCare exists.