The problem is that it's quite hard to gauge how often a post is red across multiple front ends, steemit did it because at the time there was basically only one front end. Now we have lots of readers on eccency, hive.blog, peakd, so if we were to display a page viewer feature, it would be per front end which wouldn't be very accurate.

We could have it at the api level where front ends could note whenever someone requests to read a page, but first it would easily be gamed and second sometimes posts are loaded even though they aren't red, some front ends load posts just to show the first 5 lines to incite people to read them.