Chris, I realize that leveraging the language of economics and capitalism to describe educational interactions can certainly rub many people the wrong way, but it seems to me that you are creating conflict over semantics and not substance.
As a long time progressive educator and parent I can honestly admit that I am constantly "selling" to my child, my students, and to other educators. Selling doesn't mandate and exploitive relationship. For me, it means that I'm trying to elicit behaviors in others that I believe will help them or society as a whole. From getting my daughter to eat her green beens to encouraging my colleagues to have clear learning outcomes for students ... I am trying to "sell" them on an idea they don't find intrinsically valuable.
Further, I don't think it's accurate to describe "the sales model" and the "engagement model" as opposing ideas. Engagement is a method of sales (and I happen to agree that it is one of the most effective methods). My sales pitch includes strategies like forming great relationships with students, putting things in context, making things relevant, and leveraging technology. Other less progressive educators or parents might sell learning by bundling it with something kids like (if you get a C in History, you can play football).
As a history teacher, I can testify that students have have a lot more intrinsic interest in video games than the War of 1812 does. As much as I want those kids to crave learning history (or love green beens), they don't seem to come to us that way. I do have to "compete" with things that easily capture their attention. I do have to "sell" the idea that what I want them to learn is valuable and worth their time. And if I fail to do that, it is on me and not my students.
Of course an economist is going to use economist language. A naturalist might use words like "evolution" and "ecosystem" instead. A farmer or a welder would probably use language more comfortable to them. No term or analogy is perfect. Let's not create battles over semantics. The bottom line ... with a solid education being more important than ever in determining a child's success and a shrinking safety net of high paying, low skill jobs, for kids not intrinsically motivated, educators need to find effective ways of ensuring that every student graduates with the knowledge, skills, and attributes for success. And we need lots of analogies to send that message to lots of audiences.