My theory is planned obsolescence, catering to a crowd where money is no object and new cars every 5 years is the norm. Their prestigious market does not care how long-term unreliable or expensive is to repair, because they never see that end of the relationship.
The vehicles and parts are extremely well engineered (often to their own detriment for cost effective repairability) for a short period of time. Examples include the hydraulic shocks/strut system. Great, until it stops working and the repairs are more expensive than the value of the car. Or the timing belt/chain as noted above, in the back of the engine on plastic guides which is about as stupid as you can design it for long term (admittedly other car companies are guilty of this or similar stupidity to the point it becomes nefarious). Or poorly designed transmissions...
They just break early and when they do they are really really expensive to fix. But the original owner who didn't flinch paying $100,000 for it new, and getting rid of it at year 7, doesn't care at all that it's about to fall apart at year 9 and burden the new owner with tens of thousands of dollars in repairs. That original owner has moved to the next shiny $100,000 model. And the company benefits by keeping mechanics gainfully and handsomely employed.
And some how these cars continue to maintain a unwarranted esteem reputation as people chase the appearance of wealth while the car bankrupts them... Hey, I'm guilty of it too. I have been looking at old Mercedes lately... lol.
