I am searching for a word that describes a person who complains about people who complain. I have tried numerous synonym blogs, but cannot find anything satisfactory.
Truly the behavior you describe is most often designated by the adjective “hypocritical,” while the actor noun is, of course, a "hypocrite." If the term is too harsh-sounding, you can add a modifying adverb ie, “unconsciously, unintentionally, or inadvertently hypocritical,” or an adjectival modifier with the noun, hypocrite. And, it is well worth noting, we all have our blind-spots and are, to a greater or lesser degree, possessed of this same character flaw. Much like the person you seek to describe, what we find disagreeable in another, we are often blind to in ourselves.
1. a person who pretends to have virtues, moral or religious beliefs, principles, etc., that he or she does not actually possess, especially a person whose actions belie stated beliefs.
2. a person who feigns some desirable or publicly approved attitude, especially one whose private life, opinions, or statements belie his or her public statements. See, Thesaurus.com LINK
Or, the less common designation, a "dissimulator," or one who "dissimulates"
Dissimulate verb (used with object), dissimulated, dissimulating.
1. to disguise or conceal under a false appearance; dissemble: "to dissimulate one's true feelings about a rival." verb (used without object), dissimulated, dissimulating.
2. to conceal one's true motives, thoughts, etc., by some pretense; speak or act hypocritically. See, Thesaurus.com LINK
If the complainers are continually complaining then they could be described as whingers; and since you disapprove of such behaviour then you are an anti-whinger. If you want to declaim your disapproval then you could be a whinge-denouncer or a whinge-decrier or a whinge-deplorer or a whinge-censor ...