Answer

The conclusion is too far-reaching. A halakhic decisor can decide for people in various situations, so long as these are situations he understands (that is, they are of the kind of situations he himself has experienced). When the situation is essentially different from what is familiar to him, then indeed he should refrain from issuing a ruling. He can advise and offer guidance and suggest lines of thought, but the ruling should be left to a rabbi who knows the situation or is in it himself. If the person who is actually in the situation is an ordinary person (not a Torah scholar), he cannot issue a ruling, because he lacks the knowledge. What I think should be done in such a case is to lay out for the person the entire halakhic picture, the costs and the options, and then let him decide on his own. That is how I acted several times when people asked me about family planning. I presented the picture of what is permitted and forbidden, the costs and the considerations, and left the matter to the couple's own decision. It seems to me that this is the right way to act in any case involving a private individual's question (as opposed to someone issuing rulings for the public).