Instead of taking steps to increase his odds of meeting someone he could start a relationship with, the incel is instead doing mental gymnastics to justify not even trying and instead feeling content with the status quo. If he changes his mentality from “I’m falling behind and there’s nothing I can do about it” to “I haven’t had a reason to start a relationship, and I still don’t, and probably won’t for the foreseeable future, and that’s OK,” he is bound to be more content with himself.
The key is to appear apathetic without appearing incompetent or defeated. The latter is “I choose not to” whereas the former is “I can’t.” It’s one thing to be a productive, self actualized member of society and another thing to give off virgin energy and red flags of unsuitability. The distinction, funnily enough, comes from within. The net effort to obtain a partner is 0 in both cases, but the inner paradigm shift causes a ripple effect that itself can actually lead to interest from a third party. This goes back to what his coworker tells him about genuinely not caring about the outcome of his interactions - that is, assuming he can properly separate the intention from the result without deceiving himself.
But this mental sublimation can only go so far. Even when the incel might want to indulge in a secret admirer/requited love scenario in his head, he doesn’t think there’s an ounce of possibility and therefore loses interest immediately and instead reopens old wounds - a negative feedback loop of the Pavlovian order that isn’t at all conducive to getting his ducks in a row.
Statistically speaking, he has probably had many secret admirers throughout his life that he was either too disinterested in or too oblivious to notice at the time; he is not denying that. What he is denying is the possibility of a two sided interest, simply by virtue of him simultaneously not knowing what he wants and wanting too much. Logically, if the incel exclusively longs for people that have no reason to long for him, he is always going to walk away empty handed and frustrated. Perhaps he has need to define for the first time in his life what traits an ideal partner would have, if such a person exists at all. For the time being, he is putting in too many boolean operators and getting 0 hits.