"Girl" and "boy" don't bother me. Neither does the common noun "guy." If someone wants to call himself The Avocado Guy that's IMO typical marketing silliness.
But I promised to give an example of what I consider a deal-breakingly horrid title, so here it is:
The Mensch Chef: Why Delicious Jewish Cooking Isn't an Oxymoron. It's by Mitchell Davis.
For me that's cringeworthy on several levels. For one, the Yiddish word "mensch" (or "mensh") has nothing to do with being down to earth, or pleasant to be with. The word for that is "haimish." A mensch is a human being of the highest character, a person of honesty, integrity, compassion, courage, etc. As another poster said here, all kinds of people can be good cooks. How would you like "The Sterling Character Chef"?
Furthermore, "mensh" is a noun, and it will not do to use it as an adjective. The adjectival form IIRC is "menshlike," pronounced mensh-li-kuh.
And of course "delicious Jewish cooking" isn't an oxymoron. I can't imagine a statement in which it would be an oxymoron. An oxymoron is a deliberate device to describe something that is real in spite of the contradictory words. "Sweet sorrow" (Shakespeare). "Darkness visible" and "living death" (Milton). "Nose-holding charity" (Vonnegut).
Much as I'd love to have another good Jewish cookbook, I would cringe every time I saw this one, even if it had a recipe for the world's greatest kugel.
Another kind of title I hate is anything beginning "Not Your Mother's." That seems a deliberate appeal to the arrogance of youth. Why should I welcome such an appeal onto my bookshelves?