The article is about underrated films. The ones you list are not underrated.
Most underrated: “Just Imagine”
http://www.imdb.com/title/tt0021016/?ref_=fn_tt_tt_1
Very enjoyable 1930 Sci-Fi flick
Though, as one reviewer says “Think Fritz Lang’s Metropolis as a musical comedy” it fascinates as an example of (ironically) HOW people of a time imagine a future. Great remedy for “futurists” predictions.
Oh, a young Maureen O’Sullivan too.