I think I understand where you're going with this, but I'm mostly going off the sentence:

In the same way that there is junk food that tastes good but is ultimately unhealthy for you, I believe there is ethical junk food which fills us with a feeling of virtue that is underserved [sic].

I think you're saying that we have actions that don't fulfill our moral systems as much as we feel like they fulfill our moral systems. I.e., tipping makes us feel like much better people than its fulfillment of our modern moral system justifies, whereas donating a big chunk of money to charity might actually not be making us feel as good as it should.

Or the reverse, depending on your moral system. The specific examples are beside the point - you're saying our natural sense of moral revulsion has not kept pace with the progress made on the moral systems it is trying to fulfill.

Is this about right?