What I've heard, it's a bit of a misunderstanding why the NS-10 was so popular in studios. It wasn't because they sounded like something the general population had at home, they worked more like a magnifying glass for the midrange, and if the mixing engineer didn't hear anything wrong with those speakers, the mix would most likely not sound bad on anything else.
It was also a small portable speaker that freelancing engineers could easily take with them, just for a reference if they had to work with monitors they weren't used to.
I don't think many productions were made with the NS-10 as the main monitors, a full-range speaker is needed to hear the full spectrum in most cases.
This article goes in-depth about the NS-10. If you look at the measurements they had a really good transient response, which was probably one of the things that made them a good “studio tool” among others. Fast, brutally revealing tools that made certain aspects and faults in the mix stand out, and in most cases not used as the main monitors.
Love or hate the Yamaha NS10, this unassuming little speaker has found a place in the studios of many of the world's top producers. We trace its history, and investigate why a monitor whose sound has been described as "horrible" became an industry standard.
www.soundonsound.com