“Tilting at windmills” is a euphemism for Quixotic.
“Quixotic” is often a euphemism for ‘impossible or futile effort’. Most often, the person claiming another’s efforts are futile (The Shiny Shills of QR, urp), is underhandedly trying to discourage the effort from continuing, WHILE avoiding saying outright they want the effort to stop. That person is trying to shame the other into giving up. Ironically, people who don’t ‘get’ Quixote, just like irony, don’t understand what they are saying.
The person trying to stop a worthy effort, by invoking the futility of “tilting at windmills”… is either poorly read, stupid, and/or outright evil for trying to STOP the worthy effort (no matter how seemingly impossible, futile or “Quixotic”).
Just Say’n