Apart from the fact that many people simply didn't like the feature and how it worked it also messed up the Lightbox features users had installed themselves it prevented viewers from seeing high resolution photos and caused other issues for some blogs. Not to mention that it didn't work all the time.
Bloggers understandably were pretty upset and Blogger took some steps to minimize the damage. Eventually it disabled the feature altogether and got to work on bringing it back in a way that made sense.
It's done that now Blogger is bringing back the Lightbox feature but with the option of disabling it for your blog.
Marcos Almeida a software engineer at Blogger wrote " Thanks to your feedback we turned Lightbox off temporarily and we’re re-launching it today with the option to disable it along with a handful of fixes to bugs that you reported ." .
He explained "If you’d like to disable Lightbox on your blog log in to Blogger and select 'No' next to Lightbox in the Settings >> Posts and Comments section in new interface or the Settings >> Formatting section in old interface ." .
The feature is still enabled by default but at least users have the option of disabling it which is what most people asked for in the first place.
It's great that Google moved fast to react to the feedback but the real question is why it didn't make it an optional feature in the first place and why no one anticipated that introducing a rather disruptive feature that has been met with polarized opinions in the past would not sit well with at least some of the many millions of people that use Blogger.
The logical explanation would be that either Blogger didn't realize people would not like it or it believed that the ones that would not like it were a small minority.