True detective work in the field revolves around speculation prompted by facts. Without that speculation, lazy detectives would just sit waiting for the next fact to appear, instead of going looking for it because they speculate what it might be. Detective work is all 'IF this, then that, and IF that, then something else but if NOT this or that, then back to item one '. That's speculation, logic-based. They/we have no facts to go on in the first instance beyond that MM disappeared without trace. If we don't speculate, there is no conversation. If the detectives didn't speculate, there would be no progress in this case at all. The fact that they may be entirely wrong shouldn't stop them (or us) trying, as long as everyone is open to change when new facts appear..
JMO, obviously.