Esto es el ejército

First of all, had you done your research, you would've known that all three branches of the military had (and still have) entertainment divisions whose sole job is to produce shows for the troops. If you looked at the "Crazy Credits" section you would've learned that famed composer Irving Berlin staged the two soldier shows as depicted in the movie.

Yes, many of the skits and songs are terribly dated and yes "This is the Army" is largely a propaganda film, but Berlin singing his "Oh How I Hate to Get Up in the Morning" was the lament of every draftee.

Virtually *every* film made during WWII was done either as propaganda or to bolster the spirits on the homefront.

I respectfully suggest watching it again, but instead of looking at it with 2004 cynicism, look at it in the context of the times.