ANSWER: Concerning why God does not reveal himself more to humans, the Bible says what can be known of him should be clear to anyone who studies what he has made. The clockwork mechanism of the universe, the laws of physics, the functioning of the human anatomy and so on are concrete evidences of a Creator. Those who fail or refuse to discern God and his unlimited divine power and wisdom, by observing creation, are without excuse (Romans 1:18 - 20).
One way to discover the existence of God philosophically and logically is by trying to find the answer to the repeated question, "Where did THAT come from?" Eventually, even considering the possibility of a "Big Bang" and other scientific theories concerning the universe, a person will come to the point where the only answer is either God or some other term designating a creator.
Any human who thinks the expanding universe and the complexity of all living creatures just came about through random chance and other evolutionary processes has taken a far bigger leap of faith than the 'blind' faith they accuse Christians of possessing. The necessity of a God, give all the evidence, could not be more obvious.
Why is it that he wants us to search for him? Why does he not remove all doubt about himself by coming to each of us personally and introducing Himself? One reason he does not do this is that human nature generally does not value or fully appreciate something that comes to it cheaply or without costing something (time, money, effort, etc.).
Once someone establishes the existence of God the next step is to discern the meaning and purpose of his or her lives as it relates to that Creator. This requires searching and discovering the true meaning of life. The writer of Proverbs 25 states that the Eternal knowingly conceals things so that we may search them out (Proverbs 25:2).
The Apostle Paul began his first message to those in Athens (Athenians worshipped multiple pagan gods) by stating God wants humans to search Him out because of the character it builds.
In order that they might seek the Lord (God), if perhaps they might feel after Him and might find Him; though truly, He is not far from each one of us (Acts 17:27).
Your question shows that you are on the track to finding the true God, as there are many deities (all of which are false) available for us to find. For most humans, their "deity" or "god" is the person, idea, or desire that occupies the uttermost respect and love in their minds. For some, it is sex, or money, or power, or even another human being.
There is a common flaw in most religions that state they know God, such as Zoroastrianism, Hinduism, Buddhism, Islam and even modern Christianity. This fatal flaw is that these religions give human beings a philosophical excuse for a lack of personal responsibility. It is not necessary to strive to achieve one's potential to be "saved" or to reach Nirvana.
There is an element of "magic" that is introduced in these religions that "changes" everything; human beings are “powerless" to overcome the "call" - it is completely beyond the control of the individual. One can become part of a group that believes these fantasies and pretend to be in on the magic. Such things lead to philosophical and mental stagnation and hypocrisy, and, of course, do not lead to the true God.
The Bible does reveal real answers to all the major philosophic questions such as why man exists and what is his destiny. These answers are available to those who read it with a truly open mind and heart and ask for help to understand its profound lessons. It is not easy, but any person can do it if they willing to seek God out. Finding the answers to the basic questions of life along with the strongest motivation possible to strive to reach your potential is the immediate reward for the search.
Trust in God and ask Him to help you find Him. If you seek after him you will find him and he will reveal himself to you (Matthew 7: 7 - 8, 11).