Asking a person where are they going is bad omen and many educated people still get really wild if their family members ask them.

Silly as it may sound it is again one of the ways to handle communications in the past.

I am assuming many bold and smart people would have gone out of their homes without telling or informing their elders. They would try to do some task independently and that would have been unsuccessful. 

Those unsuccessful deals or event would have cost the family elders loss of money, name or fame.

They must have felt angry or even guilty of not asking the young dude before he went away!

So these elders made a rule to ensure that the youngsters compulsorily informed, consulted or told their elders about their actions every day before they left homes. ANd what better way to ensure that everyone followed this rule.

Yes you are right it FEAR which ensures automatic following of the rules.

So these same elders decided to spread the belief that if anyone went out of the house without telling their elders about their plans, and these elders asked them just when these young dudes were leaving the house, it would be a bad omen. The work for which the young lad was setting off to will be unsuccessful. 

So slowly everyone started fearing the failure and would make sure they talked to their elders about their next day's plan. Hence when they left in the morning to act on their plans no one stopped them and they would be successful. Successful obviously as they had consulted their elders previously!  So happy ending.

But even today when the elders are told about the plans, the entire family takes part in the decision, the FEAR of asking a person where they are going prevails. And these elders who had started the Fear, have forgotten long back that the purpose was different. 

So next time you have any plans, do discuss with the elders in your family, take their advice and also mention that now even if someone asks you where you were going will not affect the success of your action as you have the blessing of the elders!