you have no proof that if God communicated directly to everyone, everyone would believe in God
The sun communicates to everybody with its light and heat. Even a blind man knows when the sun is shining. An omnipotent god, if one existed, could certainly be at least that apparent if it chose to.
I've mentioned to you in the past that the choices that this alleged god makes are always and in every case the option that would be imposed on a godless universe capable of generating and sustaining intelligent life. Every time we flip this coin, it comes up tails (the godless option is always the outcome). The coin is loaded. The god isn't doing anything. Even if gods exist and one created our universe, it would be the deist god - the noninterventionalist god.
God does not WANT humans communicating directly with Him.
How could he prevent it if he is omniscient?
Why should God care if atheists exist if atheists don't care if God exists?
What use would any of us have for such a god? If I ever choose to believe in a god, it will be a better one than that. It will be a good god and a compassionate god - the things various theists tell me is the case with their god just before describing its flaws and imperfections such as indifference to atheists - people