I think they have taken the car dealer ship model.
the same thing is evident in bmw, mercedes etc.
they consider it a premium product and don't want any old rif raf working on it, plus it protects the dealer investment.
I'm sure that's true about car dealers. And not only that, they tend to want to replace things rather than fix them*.
Case in point the last BMW we owned (and it will be the last BMW I own) had a problem with the self-levelling rear suspension (it was an E61 530d). It kept going up and down and was un-drivable when it was down as it was on the bump stops. There was clearly a problem as it burned out three alternators in a row trying to level the suspension.
It took forever for them to diagnose the problem. They couldn't do it at dealer level and the car had to be plugged in and given remote access to some super computer in Brackley.
It diagnosed it to a faulty connector. So BMW told me the ONLY solution was to replace the entire wiring loom (£1,300) and it was a 20 hour job to do it. I think the hourly rate back then was £130. Total cost was Just under £4,000 as the car was out of warranty - even though it was just 6 years old and had always been serviced by a main dealer.
At this point I was using a back-street BMW specialist as I was getting very effed off with the main dealer treatment and once it was diagnosed, he said "That's the same connector they used to use for the electric windows on the previous model. We're breaking one of those and we can just solder it on for you"
Total cost £350.
On a related note, the govt introduced a digital log book so that there's an electronic record of a car's service history. But, in our case, the garage that services our current car (Audi - which we get serviced at the same garage as above) is 'not allowed' to access the online service record as it's for Audi dealers only. So I had to buy a separate paper log book to get stamped.
*A point also backed up by my Dad who was a mechanic all his life. When he first started, they'd take things apart and fix them. By the time he retired, he said no one does that anymore - they just take things off and replace them.