My logic is sound, whereas your understanding of it may not be.
A lightbulb is indeed electrical and has a limited lifespan of course. Then again, it is a simple fix and very inexpensive. Fuses similarly so, though to be honest thay rarely go unless a problem has occured, in which case they have done their job.
In the case of the display panel, yes it obviously worked, but not long enough. Durability, as you say, is what it is all about. As mentioned in the Watchdog report, this item is a critical component for reading speed and fuel. It shouldn't fail so readily.
The fact it only affects a certain build date of cars also suggests that less than acceptable parts were used instead of whatever was used on other build dates, either with or without Renaults knowledge.
I too have had faults and problems with my Scenic and far from inspecting the mouths of gift horses, I have dealt with them myself as it was easier. There does come a point though when it feels like manufacturers are taking the consumer for mugs.
They may not have had to do anything about this at all, but the publicity forced them to.