There's no debate. There isn't an audio engineer in the world who thinks a speaker from wallmart is considered efficient. It's from the mindset of people who the first speaker spec they look at is wattage...when wattage is the LAST thing (in fact it's almost never viewed) from people who actually know something about audio.
Take a look at the top PROFESSIONAL speakers in the world. JBL, Klipsch, TAD, Tannoy....all of them produce high efficient speakers (95db's and above). There's a reason for that.