Legal to leave electrical boxes open and hanging by contractor
The room does not appear move-in ready.  Perhaps it was "left" like that because an inspection is a next step here, e.g. By the licensed electrician he'd have brought in to sign off on the work if you hadn't fired him, or by the city inspector.

Much of what electricians do is such as wiring compressor buildings in refineries, fitting main and backup power in data centers, at a mall putting in 800kva (that's more than the whole mall) of 480/3ph service to power a dozen Tesla chargers, installing mad numbers of Tesla PowerWalls for people not content with their grid-dependent systems, etc.  Those things need experienced electricians and are outbidding residential builders for the limited supply of electricians. 

As such, it's a seller's market in this building boom.  Booms tend to cause the bottom of the barrel to be scraped, creating employ for licensed electricians who aren't very good and can't get work except in these times.  

Having an apprentice wire outlets then a competent electrician inspects is perfectly reasonable, and certainly preferable to the alternative of hiring one of those bottom-of-the-barrel types, insisting an incompetent do your wiring merely because he's blessed with a government medallion.

Of course, I'm biased; I am one of those competent-but-unlicensed types... but I'm not paid to wire.