Often, the problem in dating requires one to work differently rather than harder. They are missing some facts -- people always are. So the conclusion that their decision is rational is incorrect.

That doesn't make their decision irrational, except to the degree that all complex decisions are made on the basis of incomplete information. You make the best possible induction from limited information. It becomes irrational when one believes they are making infallible deductions, which is false.

Dating may not be worth it. That's a valid choice. But it's misleading to attribute it to facts which may be false or incomplete, and leads to problems with other human interactions.