"It's interesting — very few customers are actually bent out of shape about this"
Seems to me you don't get it. Sure there are some very vocal non-customers but you also have a lot of potential customers and users (spinning up free instances) evaluating your product and hoping for a better product. I agree that your true value is the abstraction you provide. Some of these potential customers want to ensure Heroku is as good an abstraction as promised to justify the cost and commitment.
Fair enough. I think the best thing we can do for those potential future customers is be really clear about what the product does and give them good tools and guidance to evaluate whether it fits their needs.
I'd argue that we dropped the ball on that before (on web performance, at least), and are rectifying it now.