....how a computer chip works?? (Andy don't answer that) ....
Sorry Pat, can't help myself

I'll answer a question with a question: what do you need to know?
Take a carbeurettor. There are various levels of understanding:
1. Not a clue, put petrol in and it goes.
2. Can take out the jets, clean and rebuild. Know how the enricher circuit works.
3. Understand the Stochiometric ratio and how the needle shape, jets and so forth produce the three curves for idle, part throttle, full throttle etc.
4. Understand the actual flows, droplet size and so forth.
Most home mechanics/workshop technician are a 2 or possibly a 3. When you find a jet you can't see daylight through, you don't start to worry about what fuel additives and conditions make a laquer and you don't whip out your lathe and start making a new one, you go buy one. People at level 4 at the engine OEM rarely get it that wrong.
When your PC breaks, I bet no one worries about which chip is the issue, they just find the smallest supplied part to replace.
EFI and other technology just changes what you need to know. It's so simple at the workshop level that anyone who knows carbs WILL think they are being given the kiddies version. The problem is that the switch in technology has left workshop supplies in the dark ages. In 1900 I bet few home mechanics and a lot of workshops lacked vacuum gauges to balance twin carbs which left the dreaded craftsman/guesser to do his worst and there'd be letters to the Times about how anything more complicated than a bean can with a hole in the top was the work of the devil. That's where we are now because the people with the diagnostic kit like charging £50 an hour. You can buy an OBD reader from Argos, so it won't be long before most decent shops will know what they are doing and your home laptop will have some sort of software. You really don't need to know much beyond that the fact that the ECU is a black box full of angry pixies who'll talk to your PC and tell you which bit to look at next. Carbs don't tell you which bit to look at.
I'm really surprised at Yamaha getting the mapping wrong, they certainly wouldn't have supplied a carb with the wrong jetting

. BMW and the Italians I expect to underdevelop their products, but when the new Truimphs came out with a near perfect set up on day 1 and workshops that could do exhaust swaps just as they had with carbs I'd assumed the FI suppliers now knew what they were doing.
Andy