Khanh, this being your first IELTS task 2 essay, I will go easy on you by not scoring your work. Instead, I will tell you which portions of the required elements you got wrong and how you should correct it. This being a standardized test of the English language, there are certain parameters that are set for you which you cannot change.  
  
The first of these parameters has to do with the first paragraph. Known as the opening paraphrase, you this is the part of the test that is used to determine your English comprehension skills. This paragraph is the basis of whether you will pass or fail the entire test. In this case, you will have failed the entire test due to a number of reasons.  
  
A major reason for your failing has to do with the main requirement of this paragraph which is, the accurate restatement of the original prompt requirements using your own words. What you did was an immediate discussion of the prompt topic instead of an introduction for the reader. The more accurate representation of this paragraph would have been:  
  
*There is an increasing interest in learning the history of one's family in certain areas of the globe. While this trend is one that may be viewed as a negative by others, I view this as a positive trend. The reasons for my positive belief will be explained below.*  
  
When you paraphrase the prompt, you only need to represent the very same data that is within the original prompt requirement. The example I provided accomplishes that task.  
  
The other major reason for the failure of this essay has to to with the Task Accuracy portion. There are specific instructions set forth in the essay that dictate how the discussion is to proceed. In this instance, you were asked to discuss the trend of genealogy as either a positive OR negative development. You were not asked to "Discuss both points of view" as you did in your essay. Such a mistake in tackling the essay instructions proves that your English comprehension skills are not yet at the level where you will be able to handle intricate instructions from a native English speaking professor or instructor. Your inability to respond accurately to the prompt instructions will result in an automatic failing score. The mistake in your opening paraphrase led you to discuss a different essay topic from the one provided. Therefore, while you did present body of paragraphs for discussion, the discussion was not proper in context and as such, cannot be judged for passing consideration based on the remaining scoring criteria for this test.  
  
Based on these 2 major problem points, it would be in your best interest to focus your lessons on properly understanding how to discuss the various discussion presentations in an IELTS test. You can do that by reviewing the other IELTS tests on this site and learning from their discussion methods and advice coming from other users and contributors as well.  
  
Do not feel disappointed or angry. Use this essay as the inspiration to make you do better with the next one. I am sure you will show improvement because, just like all the other students reviewing for their test here, you too will learn from your mistakes and apply the corrections accordingly.