Any sort of context seems to have been lost. Looking for a partner? Then you better discriminate against the under-16s. Is the earth flat? We really aren't obliged to be 'open-minded' towards people who think this. Apart from anything else, open-mindedness like this must surely be rather inefficient.
Appropriate closed-mindedness allows doctors not to waste time on the possibilities that the patient before them is ill because they were abducted by aliens the previous evening, or they're possessed by a demon, or have been disabled by a witch-doctor or something. And mechanics can fix cars more quickly if they dismiss the suggestion that engine failure is down to fact that the driver's ying was out of sync with his yang.
The topic was homeopathy; the truth is universal.