I don't think the issue is with the fact that they are data-mining purchasing habits. I think it's the way they acted on it without any subtlety.

  > they're choosing to publish the data (their purchasing habits)
  > simply by making the purchases

I would not call it 'publishing.' In this case, the girl's purchasing habits were really only between her and Target. Target then inadvertently disclosed them to her father.

  >  Similarly, Google and Facebook track you to show
  > you more relevant ads, and thus increase conversions.

Google/Facebook would be wise not to fill your browser with ads about herpes medication just because they think that you have herpes... Just sayin'.

  > if the data is obviously collectible, you
  > should assume it's being collected.

This isn't free license to say that data collecting is good or bad though. If you walk through the 'bad part of town' wearing expensive jewelry, you'll probably be robbed. That doesn't make robbery acceptable.