Can you explain the reasons why an individual never finds the work to lead to desired results for the house, which is occupied by Ketu in the natal chart and why it always remains a void?
It is not correct. The results of Ketu depend upon the strength of its lord if it is in a moolatrikona sign and the level of affliction being caused by Ketu. For example, Ketu is in the third house of Prof V K Choudhry, which rules younger brothers, (he has three), it rules courage (he has much more than the average person) communicative skills (for others to judge), writing capabilities (he has written twelve successful books) and hundreds of articles for various magazines.