The short answer : Because of your freedom.
God does not hide from you but he respects your freedom. He won't talk to you if you don't want to. Making you believe, he could, but he wants you to chose him freely.
Well, let's start this again, then.
There are a few obvious reason why God would not talk to us in an obvious manner
(1) He's not there
(2) He wants to find telepathic humans, which he has spent 50,000 years breeding
(3) He is selecting only 144,000 perfect humans, so only the God receptive ones succeed
(4) He's waiting for humans to invent the true religion, at which point he will start talking. This is not implausible, since he supposedly waited to send Moses and Jesus
(5) .... I can probably keep making up reasons
However, "free will" is not one that is a logical reason, because (1) it's not scripturally supported, and (2) those who believe in God for some arbitrary reason, no longer really have free will, or now have a different type of informed free will.
If "free will" was scripturally supported, we would have passages such as "And God gave people a free will to believe in him or not, because to compel people would be against his ethics". Instead, in the Hebrew scriptures, we get threats. Then in the NT scripture we get more threats, and the implication that Jesus is proof that God exists, and anyone who doubts this is evil. Therefore, the mentality of the NT is proof based
, rather than free will based. We don't get missionaries telling Africans that they have the free will to believe in God. They say, instead, that God will send you to hell, if you don't believe our proof that Christ is God. If you argue that Jesus is poorly documented, then out come the proof-based arguments about martyrs and people who meticulously maintained scripture, and wouldn't lie. The assertion of Christians, is always that Jesus is irrefutable.
To come along and then say that God made proof of Jesus deliberately tenuous, so that we would have the free will to believe, is stretching credibility a bit thin.
Make up your minds, eh?