Thanks for the kind replies, all.
When I visited the Apple Store with our company's CEO, we were pretty clear that as a writer, the keyboard issues were an unacceptable pain point for me and I'd already moved onto another machine. However, the rest of our company still uses all Macs, and we were happy to take a credit for the defective MacBook Air and reconsider the lineup whenever Apple does address these issues. (I almost wrote "inevitably addresses," but we are three generations in here ...)
But their refusal to offer any acceptable remedy soured us so much that not only can I not imagine considering any MacBook in the foreseeable future, but our CEO is considering moving the entire company away from Apple. We have all been hardcore Mac users for many years, and several members of our company met while working together at what began as a Mac-only B2B software startup.
It's probably true that Apple realizes they are losing Mac customers, but they must see the consequences of this as trivial. If there are people at Apple who consider this to be a major problem, they don't appear to be in decision-making positions at the company. But it would be very short-sighted to assume that losses in the Mac division will be limited in impact to the Mac division.
Just as positive word of mouth brought exponential numbers of new users to the platform, negative word of mouth will
exacerbate the negative market effects that Apple is already suffering.