I think how the data is used is also a big factor.

There is 'justice' in the blog creator using analytics data to to improve the experience of blog visitors: a user's data will, theoretically and in aggregate, create a better experience for that user in the future. The class of 'users who browse this page' gets a benefit from the cost of providing data.

Selling browsing information to advertisers is sort of 'anti-justice'. Using blog visitor data to track and more effectively manipulate those visitors elsewhere on the internet into paying people money. The blog visitor's external online experience is made worse by browsing that blog.