shoddiness vs ineptitude

shoddiness and ineptitude both are nouns.

Word	Noun	Adjective	Verb	Adverb
shoddiness	Yes	No	No	No
ineptitude	Yes	No	No	No

As nouns, ineptitude is a hypernym of shoddiness; that is, ineptitude is a word with a broader meaning than shoddiness:

Other hypernyms of shoddiness include worthlessness.

shoddiness (noun)	ineptitude (noun)
the property of weakness by virtue of careless construction	having no qualities that would render it valuable or useful
the quality of being cheaply imitative of something better	unskillfulness resulting from a lack of training