It may be "flexible" or their hand was forced. I know, personally, at least half a dozen people who have either delayed a Macbook purchased or outright moved to PC alternatives (e.g. XPS 13, Surface Laptop) because of the poor keyboard (both reliability and touchbar).

Now six people isn't statistically significant, but if that trend mirrors a wider one it could be costing Apple a measurable amount. The real question is will this be enough to satisfy e.g. programmers that actually want to bind the F keys to build/clean/run/step over/etc?

Follow the money. It was cheaper to stick with that design for 3 iterations than it was to change it.

It takes a long time to get a design through the point of manufacture... especially at that scale. And even before that happens, an organization needs to admit that it has to happen in the first place. For everybody saying the keyboard sucked and needed improvement, there were at least a few people within Apple that had staked something on the design as it was.

We devs are so conservative. It's ridiculous. Nobody allows Apple to innovate.