How does it take away our "free will" for God to reveal Himself to us as He did with Moses?

Many people say that God doesn't just reveal himself to us because that would take away our "free will". I don't understand why that would be true. Even though His revealing Himself to us would make it very evident that He does exist, don't we still have the ability to choose to reject Him? That would mean that our "free will" is still intact. Isn't that what the idea of "free will" is about, God does what He can to guide us to righteousness and THEN we choose if we want to be righteous?